TRIPOLI Russia accused France on Thursday of committing a "crude violation" of a U.N. weapons embargo by arming Libyan rebels, while Washington said it was acting legally, creating a new diplomatic dispute over the Western air war.
France confirmed on Wednesday that it had air-dropped arms to rebels in Libya's Western Mountains, becoming the first NATO country to acknowledge openly arming the insurgency against Gaddafi's 41-year rule.
France, Britain and the United States are leading a three-month-old air campaign which they say they will not end until Gaddafi falls. The war has become the bloodiest of the "Arab Spring" uprisings sweeping North Africa and the Middle East.
Rebels acknowledged French support, saying it had helped sustain them in the region.
"There should be no doubt that Libyans in the Nafusa Mountain (Western Mountains) area are alive and safe today thanks to a combination of heroic Libyan bravery and French wisdom and support," Vice Chairman Abdul Hafeedh Ghoga of the Transitional National Council said in a statement of thanks to French President Nicolas Sarkozy.
Though rebel advances have been slow, the insurgents scored a success in the region on Sunday in pushing to the outskirts of Bir al-Ghanam, within 80 km (50 miles) of Tripoli.
On Thursday the rebels surveyed the strategic town from a ridge overlooking the desert plateau that leads to the capital, in preparation for a possible attack. A Reuters journalist with them said they were waiting for NATO airstrikes to help them.
Libyan television broadcast a statement from tribal leaders condemning Sarkozy over the arms, calling the rebels in the Berber area "a product of France."
Russian Foreign Minister Sergei Lavrov said Moscow "asked our French colleagues today whether reports that weapons from France were delivered to Libyan rebels correspond with reality."
"If this is confirmed, it is a very crude violation of U.N. Security Council Resolution 1970," he said. That resolution, adopted in February, imposed a comprehensive arms embargo.
Paris said on Wednesday it believed it had not violated the U.N. embargo because the weapons it gave the rebels were needed to protect civilians from an imminent attack, which it says is allowed under a later Security Council resolution.
Washington agreed. "We believe that U.N. Security Council resolutions 1970 and 1973, read together, neither specified nor precluded providing defense materiel to the Libyan opposition," State Department spokesman Mark Toner said.
"We would respectfully disagree with the Russian assessment," he added. Nevertheless, although legal, arming the rebels was "not an option that we have acted on," he said.
Although Russia is not involved in the bombing campaign, its stance could add to reservations among some NATO countries wary over an air war that has lasted longer and cost more than expected. Moscow could also challenge Paris at the U.N. Security Council, where both are veto-wielding permanent members.
U.N. spokesman Farhan Haq said it was up to the Security Council to determine what is permitted by its resolutions.
France's weapons airlift, while possibly increasing the insurgent threat to Gaddafi, highlights a dilemma for NATO.
More than 90 days into its bombing campaign, Gaddafi is still in power and no breakthrough is in sight, making some NATO members feel they should help the rebels more actively, something the poorly-armed insurgents have encouraged.
But if they do that, they risk fracturing the international coalition over how far to go.
The World Bank's Libya representative said on Thursday Islamist militants could gain ground if the conflict wears on.
"If this civil war goes on, it would be a new Somalia, which I don't say lightly," said Marouane Abassi, World Bank country manager for Libya who has been in Tunisia since February.
"In three months we could be dealing with extremists. That's why time is very important in this conflict, before we face problems in managing it."
Even before news of the French arms supply emerged, fissures were emerging in the coalition with some members voicing frustration about the high cost, civilian casualties, and the elusiveness of a military victory.
Gaddafi says the NATO campaign is an act of colonial aggression aimed at stealing the North African state's oil. He says NATO's U.N.-mandated justification for its campaign -- to protect Libyan civilians from attack -- is spurious.
FRANCE ACTS ALONE
NATO Secretary General Anders Fogh Rasmussen made clear on Thursday the weapons airlift was a unilateral French initiative. Asked by reporters on a visit to Vienna if NATO had been involved, he answered: "No."
"As regards compliance with the U.N. Security Council resolution, it is for the U.N. sanctions committee to determine that," Rasmussen said.
The rebel advance toward Tripoli's southwest outskirts from the Western Mountains has not been matched by progress toward the capital from the east, where they hold Misrata on the coast about 200 km (130 miles) from the capital.
The city has been bombarded for months by Gaddafi's forces. Six rockets landed early on Thursday near the oil refinery and port. A Reuters journalist there reported no casualties.
Britain's military said its Apache helicopters had attacked a government checkpoint and two military vehicles near Khoms, on the Mediterranean coast between Misrata and Tripoli.
Insurgents say Gaddafi's forces are massing and bringing weapons to quell an uprising in Zlitan, the next big town along the road from Misrata to the capital. Rebels inside Zlitan said they mounted a raid on pro-Gaddafi positions on Wednesday night.
"(We) carried out a violent attack last night on checkpoints ... and exchanged gunfire, killing a number of soldiers," a rebel spokesman, who identified himself as Mabrouk, told Reuters from the town.
Le Figaro newspaper said France had parachuted rocket launchers, assault rifles and anti-tank missiles into the Western Mountains in early June.
A French military spokesman later confirmed arms had been delivered, although he said anti-tank missiles were not among them. Despite the diplomatic storm, the rebels encouraged more arms deliveries.
"Giving (us) weapons we will be able to decide the battle more quickly, so that we can shed as little blood as possible," senior rebel figure Mahmoud Jibril said in Vienna.
The conflict has halted oil exports from Libya, helping push up world oil prices. Jibril said it may take years for oil exports to fully resume: "No, no oil is being sold. A lot of the oil well system was destroyed, especially in the east."
(Additional reporting by Hamid Ould Ahmed in Algiers, Andrew Hammond in Tunis, Maria Tsvetkova in Moscow, Fredrik Dahl and Michael Shields in Vienna, Chris Buckley in Beijing, Andrew Quinn in Washington and London bureau; Writing by Christian Lowe and Andrew Hammond; editing by David Stamp)