WASHINGTON - President Donald Trump’s orders Wednesday to start building a southern border wall and step up immigration enforcement sets the stage for confrontations with Mexico, with so-called sanctuary cities and with members of Congress who must finance his far-reaching plans.

Following through with promises that helped him win the White House, Trump issued a pair of executive orders that amount to a dramatic shift in policies under Barack Obama and a further move away from the immigration reform proposals that stood on the verge of passing Congress in 2010.

In addition to calling for “immediate” construction of the wall, the president also ordered: new detention centers; 5,000 new Border Patrol agents; 10,000 more Immigration and Customs Enforcement personnel; and an end to what detractors refer to as a “catch and release” policy for immigration law violators.

His two orders did not estimate the cost of a complete border wall — 650 miles of wall and fencing already exist on the 2,000-mile border — or of hiring the thousands of agents and building more detention centers. South Texas already is home to two large family detention centers in Dilly and Karnes County. Estimates of completing the wall alone have been up to $15 billion or more.

The long-anticipated executive orders, part of what Trump promised as soon as he took office, also come at a time when illegal immigration — measured by apprehensions at the border — has plunged to its lowest level since early 1970s.

“We’re in the middle of a crisis on our southern border. The unprecedented surge of illegal migrants from Central America is harming both Mexico and the United States,” Trump said, speaking at the Homeland Security Department.

“A nation without borders is not a nation,” he said. “Beginning today, the United States of America gets back control of its borders, gets back its borders.”

The president, flanked by Vice President Mike Pence and newly installed Homeland Security Secretary John Kelly, introduced families of several victims of undocumented immigrants whose stories, he contended, were not told by “pundits.”

Not all Republicans share Trump’s enthusiasm. U.S. Rep. Will Hurd, R-San Antonio, who has 800 miles of border in his district, called the wall “the most expensive and least effective way to secure the border.”

Hurd said in a statement that a wall might be effective in densely populated areas but that in places like Big Bend National Park it “is unnecessary and would negatively impact the environment, private property rights and economy. There is no question that we must secure our border, but we need an intelligence-led approach.”

U.S. Rep. Henry Cuellar, D-Laredo, said Trump was “opening a Pandora’s Box” with his orders and his “America’s First” assertions, threatening foreign trade and emboldening Mexico and countries around the world to assert that they, too, will operate in their own self interests.

Cuellar, the only Democrat from the Southwest on the House Appropriations Committee, said some of the Republicans he asked to deny funding told him, “‘sorry Henry, we have to go with Trump.’”

“I’m hoping that they won’t be worried they’ll be tweeted at by Trump and decide to do the right thing,” Cuellar said in an interview.

U.S. Rep. Joaquin Castro, D-San Antonio, called the wall “a lazy and ineffective strategy...President Trump’s actions represent a hostility toward Mexico, one of our oldest allies and trading partners. He is driving Mexico into China’s arms. I expect that whatever President Trump takes away from Mexico, China will step in to offer.”

But U.S. Rep. Lamar Smith, R-San Antonio, an ardent supporter of border enforcement, said he appreciated Trump “honoring his commitment” on immigration.

“Close to half a million illegal immigrants cross our borders every year. They take jobs away from American workers and reduce the wages of other American workers. They often use government services, which costs American taxpayers,” Smith said in a statement.

Working with Mexico

Trump referred at several points during his speech to the benefits to Mexico from his new policies. Mexican leaders have steadfastly rejected Trump’s assertion that their country must pay for the wall, a topic that is expected to come up again next week when President Enrique Peña Nieto visits the White House.

Trump said those discussions also would include “dismantling of cartels and keeping illegal weapons and cash from flowing out of America and into Mexico.”

“I want to emphasize we will be working in partnership with our friends in Mexico to improve safety and economic opportunity on both sides of the border,” he said. “I have deep admiration of the people of Mexico and I greatly look forward to meeting again with the president of Mexico.”

Trump threatened in his campaign to scuttle the North American Free Trade Agreement and impose punitive duties on Mexican products, more proposals that have riled Mexican leaders because of their potential for economic harm.

In his speech, the president asserted: “We are going to save lives on both sides of the border and we also understand that a strong and healthy economy in Mexico is very good for the United States.”

Trump made no mention ofthe Deferred Action for Childhood Arrivals (DACA) program that has given nearly 750,000 undocumented immigrants who arrived in the United States with their parents protection from deportation and eligibility for work.

That omission from his initial border strategy and statements Wednesday from the White House reinforced the sense that the president has no immediate plan to follow through with a promise to cancel the five-year-old program.

White House spokesman Sean Spicer said Wednesday that the president’s priorities “first and foremost are the people in this country who seek to do us harm” and that he intends to take a “humane” approach toward DACA.

“The president understands the magnitude of this problem. He’s a family man; he understands, he has a huge heart, he understands the significance of this problem,” he said.

Emergency funding

Trump endured criticism recently when Republicans in Congress began devising ways to pay for the wall. During the campaign, he left the impression that the cost would be borne by Mexico before the wall was built. He has since vowed since that Mexico will reimburse the U.S. Treasury.

Republicans talked of tacking on an appropriation to a funding bill that needs to pass by April to keep the government running.

But U.S. Rep. Michael McCaul, R-Austin, chairman of the House Homeland Security Committee, said Wednesday the GOP-run Congress intends to pass an emergency funding bill that would pay for initial construction and other security measures Trump demands.

“He (Trump) wants to move at lightning speed and be very decisive. He’s going to have to work with the Congress, whether he likes it or not,” McCaul said in a television interview.

Trump, in an interview with ABC News that aired Wednesday, said: “But I’m just telling you there will be a payment; it will be in a form, perhaps a complicated form.”

Dan Stein, president of the Federation for American Immigration Reform (FAIR), called the president’s initiatives “a historic, much-needed course correction in America’s approach to immigration policy, which has been on autopilot for decades.”

FAIR has aggressively promoted cutting off funds to cities and states in cases where undocumented immigrants are shielded. The organization issued a report recently identifying some 300 jurisdictions with so-called “sanctuary policies,” including the San Antonio Police Department.

Spicer, the White House spokesman, said among the president’s new orders is a directive to the Homeland Security Department “to look at these funding streams and figure out how they can be cut off.”

San Antonio Mayor Ivy Taylor sent a memo Wednesday to her council colleagues, outlining the city's position on “sanctuary cities,” noting the issue has been elevated by national media and the federal government.

Though Taylor said San Antonio doesn't use the term “sanctuary city” to describe local policies, she said “SAPD does not question the immigration status of individuals.”

On the border

Attorney Ricardo de Anda lives outside of Laredo in a house overlooking the Rio Grande. His property includes rivervega, or floodplain, where construction isn’t allowed or feasible. A wall there would have to be built on ground above the floodplain, cutting him off from parts of his property where his family hunts, camps and holds gatherings, de Anda said. He also draws water from the river for use at his house.

“As far as ranchers down here are concerned, that’s big government at its ugliest form, confiscation of private land,” he said.

The wall would be “ineffective” and a “logistical nightmare,” de Anda said, “and would likely be counterproductive to the extent that we would have to build roads along the wall to maintain it in areas that are inaccessible to vehicles at this time, making it easier for people who get over the wall to get on from there.”

He questioned the need for more Border Patrol personnel, saying he lives “probably in the safest part of the county” because of the number of agents patrolling the river, but de Anda said he preferred increasing the law enforcement presence to constructing a wall.

Trump’s order about the wall lacked specifics, describing it as “a contiguous physical wall or other similarly secure, contiguous and impassable physical barrier.”

Laredo Mayor Pete Saenz said that he’s hopeful local governments can work with the federal government to build a barrier only where needed.

“We’re not totally against any barrier,” Saenz said. “Fencing, if it’s done properly, strategically, it’s not as offensive as a big, deep and wide wall. We’re willing to compromise.”

He suggested that there are parts of Laredo where fencing could be built, but also urged Trump to consider the so-called “virtual wall” that relies on technology to identify people crossing the border.

Saenz said he is concerned about the message Trump is sending to Mexico.

“Texas’ No. 1 trading partner is Mexico, and we rely heavily on that,” he said of Laredo’s economy. “I would remind him that Texas is very much part of the U.S. and we need jobs as well.”

One of the easiest changes for Trump to make would be to loosen the guidelines the Obama administration put on who ICE agents can deport. Under Obama, agents were instruction to only deport immigrants who were suspected of being terrorists or gang members, had been convicted of serious crimes or had entered the U.S. illegally or been ordered deported after Jan. 1, 2014.

Ending what Trump called “catch and release” for the Border Patrol would be more difficult, said Jaime Diez, an immigration attorney in Brownsville. Some immigrants are released on bond or under some sort of supervision because ICE doesn’t have enough bed space to hold them, Diez said.

Unaccompanied immigrant children apprehended by Border Patrol by law must be turned over to the Office of Refugee Resettlement, and a federal judge in California has ruled that the government cannot hold families for extended periods of time.

“There’s a lot of things that they cannot do, that they will not be allowed to do, because there are laws, there are treaties, that they cannot undo with just an executive action” Diez said. “It creates a lot of panic in the immigrant community, because they do not know how far the government can go.”

Activists worried that Trump’s orders coupled with thousands of new immigration offers marked the beginning of mass deportations.

Janet Murguia, president and CEO of the National Council of La Raza, told reporters in Washington said she also feared that “they will unleash a wave of harassment, profiling and discrimination against citizens and noncitizens alike.”

Staff Writer Josh Baugh contributed to this story.

bill.lambrecht@hearstdc.com