SOCHI, Russia (AFP/Reuters) - Russia and NATO on Monday failed to narrow their differences over the Western air campaign in Libya, as alliance warplanes stepped up their bombing of regime targets. Russian Foreign Minister Sergei Lavrov accused NATO of interpreting a UN resolution in any way it wished, after talks with NATO chief Anders Fogh Rasmussen that showed up differences rather than any agreement on a solution. The previously scheduled NATO-Russia Council meeting in the Black Sea city of Sochi was joined at the last minute by South African President Jacob Zuma but his presence did not appear to help bring the sides any closer. "So far, there is no common understanding over how the resolution is being implemented," Lavrov said, referring to the UN Security Council resolution that paved the way for the air campaign. "We want this resolution to be fulfilled literally, without expanding its interpretation." Lavrov and Russian President Dmitry Medvedev earlier held talks with Rasmussen in Sochi in a bid to overcome their differences and find a peaceful solution to the Libya crisis. They were also joined by Zuma who earlier had a bilateral meeting with Medvedev and like Russia is pushing for a peaceful solution to the conflict. Russia abstained in the resolution vote at the Security Council but has since expressed growing anger over the duration and intensity of the NATO-led air strikes against targets of Moamer Gaddafi's Libyan regime. "We consider the arms embargo (under the UN Security Council resolution) to be unambiguous," said Lavrov. "Any weapons deliveries are a violation of the resolution," he added. Rasmussen however vehemently defended the arms drop and said it was in line with the resolution. "The delivery of weapons has taken place as part of protection of civilians and the ability to protect themselves against attacks," he told reporters. Zuma told Medvedev that meeting with NATO "would be very helpful in terms of our interaction, because they might come to know what preoccupies the AU at the moment". Meanwhile, the Libyan government said on Monday that it was in talks with opposition figures but there seemed little chance of a swift end to the civil war as both sides stuck to entrenched positions on the fate of Muammar Gaddafi. The leader's son Saif al-Islam, in combative form, told a French newspaper there was no question of negotiating an end to his father's 42-year rule, while the rebels, stepping back from a hint of a concession, renewed their demand that he go now. A spokesman for Gaddafi's administration said high-ranking government officials had been in foreign-mediated talks in Italy, Egypt and Norway with opposition figures to try to find a peace deal, and that talks were still going on. Any talk of a possible accommodation with Gaddafi could drive a wedge into the ranks of the disparate rebel movement which sprang up in February in the wake of uprisings in neighbouring Tunisia and Egypt. Many of Gaddafi's opponents are flatly opposed to any form of concession to the veteran leader. Saif al-Islam Gaddafi, one of the most prominent of the leader's sons, dismissed suggestions that there could be a peace settlement that removed his father - a demand not only of the rebels but of the Western powers bombing Libya since March. "My father is not part of the negotiations," Saif al-Islam told Le Monde newspaper. "You think one can find a solution that does not involve him? No, it's impossible." By backing the rebels, NATO had picked the losing side, he added: "God is with us. We will fight and we will win. "We have our army. We have more munitions, more weapons. Morale is high. The others are becoming weaker and weaker." A glimmer of concession on Gaddafi's future from the National Transitional Council on Sunday was swiftly withdrawn on Monday when the NTC, based in the eastern city of Benghazi, contradicted remarks made by its leader Mustafa Abdel Jalil. He told Reuters on Sunday: "As a peaceful solution, we offered that he can resign and order his soldiers to withdraw from their barracks and positions, and then he can decide either to stay in Libya or abroad. "If he desires to stay in Libya, we will determine the place and it will be under international supervision. And there will be international supervision of all his movements." However, on Monday issued a statement by Abdel Jalil saying: "I would like to confirm that there is absolutely no current or future possibility for Gaddafi to remain in Libya ... There is no escape clause for Gaddafi - he must be removed from power and face justice." In Misrata, a rebel-held city 200 km (130 miles) east of Tripoli, there was renewed fighting on the southern outskirts. Doctors told a Reuters journalist that two fighters had been killed, adding to two whom rebels said were killed on Sunday. The closest rebel position to Tripoli is near the town of Bir al-Ghanam, about 80 km (50 miles) south of the capital. There, rebels say they are preparing an offensive, but there has been little movement for over a week. "The situation there is relatively calm, the revolutionaries are preparing for the next days," a rebel spokesman called Mohammed told Reuters from the nearby town of Nalut.