Libyan rebels who control three oil ports will not enter any talks with the government about ending their blockade unless Tripoli returns a tanker that loaded oil at one of its terminals but was recaptured by U.S. forces, they said on Monday, Reuters reported.
Two weeks ago, the rebel militia managed to load crude onto a tanker docked at the Es Sider port, one of three it seized last summer to press the government for a share of oil revenues and regional autonomy.
The Morning Glory arrived in the Libyan capital on Sunday after U.S. special forces stormed the tanker and handed it over to Libya's nascent navy.
The government has told the militia to negotiate an end to their port blockade or face a military offensive.
Abb-Rabbo al-Barassi, self-declared prime minister of the group, told a local television station that, first, Tripoli must return the tanker and three rebel fighters who had been on board.
"We set as a condition that the tanker and those on board must return in safety before any dialogue," he said, in the group's first reaction since the tanker arrived in Tripoli.
He said the militia would prove that is was able in future to protect any tanker buying oil from its ports.
"We realize that the world respects only those with force. That's why will add strength and equipment," he said, without elaborating.
The port blockade is one of many challenges facing the government which has failed to secure the country three years after the fall of Muammar Gaddafi.
Former anti-Gaddafi rebels and militias refuse to surrender their weapons and often use force or control of oil facilities to make demands on a state whose army is still in training with Western governments.
Those governments, which backed NATO air strikes to help the 2011 anti-Gaddafi revolt, are pressing the factions to reach a political settlement.
Libya's oil production has fallen to a trickle due to the port seizures and protests at major oil fields.