Russia has criticised France for air-dropping weapons in Libya's rebel-held areas, saying it violated a United
It said on Thursday that France has committed a "crude violation" of a UN weapons embargo.
Sergey Lavrov, Russia's foreign minister, said his ministry had asked France for further details. "We are awaiting a response. If it is confirmed, it's a flagrant violation", of the resolution, he said.
Russia and China have both questioned whether or not the supplying of weapons breached the terms of the United Nations Security Council resolution that authorises international action in Libya.
China, without naming France, said that nations should not overstep the remit of the UN resolutions.
Hong Lei, China's foreign ministry spokesman called on "the international community to strictly follow the spirit of the relevant resolution of the UN Security Council and avoid taking any action that goes beyond the mandate of the resolution".
"We are awaiting a response. If it is confirmed, it's a flagrant violation"
Sergey Lavrov, Russia's foreign minister
But Mark Toner, a US State department spokesman, told reporters in Washington that the US would "respectfully disagree" with the Russian assessment in a move that threatens to become a new diplomatic dispute over the western air war.
"We believe that UN Security Council Resolutions 1970 and 1973, read together, neither specified nor precluded providing defence material to the Libyan opposition," he said.
France confirmed on Wednesday that it had air-dropped arms to rebels in Libya's western mountains, becoming the first NATO country to openly acknowledge arming the rebels against Muammar Gaddafi's 41-year rule.
Rebels acknowledged the French support, saying it had helped sustain them in the region.
"There should be no doubt that Libyans in the Nafusa Mountain area are alive and safe today thanks to a combination of heroic Libyan bravery and French wisdom and support," Abdul Hafeedh Ghoga, vice chairman, of the Transitional National Council said in a statement of thanks to French President Nicolas Sarkozy.
Meanwhile, a Libyan opposition leader said on Thursday that rebels needed more weapons and funding even as the head of the African Union expressed concern over the flow of weapons into Libya.
AU criticises foreign intervention
AU Commissioner Jean Ping, who chairs a meeting of African leaders in Malabo, Equatorial Guinea, on Thursday, said that weapons distributed in Libya would contribute to the "destabilisation" of African states.
"What worries us is not who is giving what, but simply that weapons are being distributed by all parties and to all parties. We already have proof that these weapons are in the hands of al-Qaeda, of traffickers," Ping said.
Colonel Thierry Burkhard, a spokesperson for the French general staff, told Al Jazeera on Wednesday that the military had dropped assault rifles, machine guns and rocket-propelled grenade launchers to groups of unarmed civilians in western Libya it deemed to be at risk.
Earlier on Wednesday, the Le Figaro newspaper and the AFP news agency reported that France had dropped several tonnes of arms, including Milan anti-tank rockets and light armoured vehicles.
The airdrops arrived somewhere in rebel-held towns in the Nafusa mountains, which run east-west from the Tunisian border around 100km south of the capital Tripoli.
Rebels control most of the Nafusa, up to the town of Yafran, while regime forces loyal to Libyan leader Muammar Gaddafi still hold Gharyan, a key town that lies astride the north-south road to the capital.
NATO Secretary General Anders Fogh Rasmussen said on Thursday that the military alliance was not involved in the French airdrop operation.
Asked whether he knew of any other countries who were supplying weapons to rebel-held regions, Rasmussen said he had "no information".
UN resolution mandate
On March 19, a coalition of countries launched a military intervention in Libya under the mandate of a United Nations Security Council resolution aimed at protecting civilians from the onslaught launched by Gaddafi after mass protests broke out against his rule in mid-February.
The Security Council resolution established a no-fly zone, asset freeze and arms embargo on Libya and various regime entities.
The terms of the NATO-led mission in Libya have provoked controversy for months. The UN resolution 1973 authorising action says the NATO operation is to protect civilians, but France's admission raises major questions about how far that mandate goes.
Part of the UN resolution allows NATO the legal ability to provide weapons for protection or defence, but if those weapons are then used for attack, the rebels and those arming them could be criminally liable.
Donald Rothwell, a professor of international law at the Australian National University, told Al Jazeera that France's arms-supplying operations might arguably fall within the mandate.
"I think one of the key issues are whether the weapons supplied by the French are defensive weapons, or whether they're supplied with offensive use in mind," he said.
France has taken a leading role in organising international support for the uprising against Gaddafi's four-decade-old rule, and French and British jets are spearheading a NATO-led air campaign targeting his forces.
Rebel forces are mainly based in Benghazi in the east of the country, and hold a besieged enclave supplied by sea in the western coastal town of Misurata, but have been unable to mount a convincing advance on the capital.