Gaddafi called his enemies "traitors and agents of the colonialism"
Libya's fugitive ex-leader Col Muammar Gaddafi has said he is ready to fight a long guerrilla war, in an audio message carried by a loyalist TV channel.
It was the second message in one day purporting to be from Col Gaddafi, whose whereabouts remain unknown.
Anti-Gaddafi forces encircling the city of Sirte have given loyalists an extra week to negotiate their surrender.
Meanwhile, Western leaders have urged the interim authorities to engage in reconciliation with their enemies.
Delegates from 63 countries met to discuss Libya in Paris, on the 42nd anniversary of Col Gaddafi's emergence as the leader of the coup that overthrew King Idris.
The colonel has not been seen in public for months, and it is not known where he is hiding.
His messages were broadcast on the Syria-based al-Rai television.
He vowed to fight "a long, long drawn out war" against what he called the occuption of Libya.
"The people will not allow you to take the oil and rob Libya's wealth that God has endowed Libya with," he said, claiming 2,000 tribes stood ready to defend Libya.
"Prepare yourselves for a gang and guerrilla war, for urban warfare and popular resistance in every town to defeat the enemy everywhere."
He said Tripoli would be "liberated inch by inch", but that his hometown of Sirte - which remains in loyalist hands - was now the capital city of Libya.
Al-Rai, based in Damascus, has repeatedly broadcast propaganda messages from the Gaddafis.
Earlier in the week Col Gaddafi's wife, two of his sons and his daughter fled to neighbouring Algeria.
And Algerian media reported that Col Gaddafi had also tried to seek refuge there.
According to a report in El Watan newspaper, the colonel tried to speak to Algerian President Abdelaziz Bouteflika from the desert town of Ghadamis, just on the Libyan side of the border, but the Algerian leader refused to take the telephone call.
Anti-Gaddafi forces have encircled Sirte and threatened to launch a full military assault if Gaddafi loyalists had not surrendered by Saturday, but officials say they will allow another week to negotiate a peaceful settlement.
The NTC controls most of the country, after a dramatic assault on Tripoli last week in which the capital fell after an operation co-ordinated with Nato air strikes.
Assets unfrozen
Meanwhile, members of the NTC met senior international diplomats at the Paris summit, hosted by French President Nicolas Sarkozy and British Prime Minister David Cameron.
Nicolas Sarkozy: "The participants are going to ask the NTC to undertake a process of reconciliation and of forgiveness"
Mr Sarkozy said everyone had agreed to unfreeze assets blocked when Col Gaddafi was still in power.
"After going around the table, it's about $15bn of Libyan assets in our countries that are immediately unfrozen," he said.
The EU announced on Thursday that it had lifted sanctions on 28 entities - including oil firms and port authorities - to help the NTC get the economy moving again. The decision will take effect on Friday.
The UK, US and France have unfrozen more than $5bn (£3bn) in Libyan assets this week, and other countries are making similar moves.
On the diplomatic front, Russia is the latest nation to agree to recognise the NTC as Libya's legitimate government.
African Union spokesman Noureddine Mezni said the pledges made by the NTC at the Paris summit were "encouraging".
The AU has not formally recognised the NTC although some of its member states have individually. It has expressed concern about Nato's military intervention in a domestic conflict. South Africa, a key AU member, boycotted the talks.
"These commitments meet our concerns and the AU will, in due time, bring them to the attention of members states," Mr Menzi told the AFP news agency.
He told Reuters he was reassured by the commitments made to protect African workers in Libya, who have faced potential attacks by Libyans who accuse them of being mercenaries for Col Gaddafi.
About 60 countries attended the "Friends of Libya" forum in Paris on Thursday afternoon, along with UN Secretary-General Ban Ki-moon.
