Moscow. Moscow has called for an independent investigation by United Nations experts into allegations that the Syrian government carried out a deadly chemical weapons attack on the outskirts of Damascus.The statement, released by the Russian foreign ministry on Friday, said Sergey Lavrov, the foreign minister, and the US secretary of state, John Kerry, had discussed the situation by telephone on Thursday and concluded that they had a "mutual interest” in calling for the UN investigation.The statement said Russia had called for President Bashar al-Assad’s embattled government to co-operate with an investigation, but questions remained about the willingness of the opposition, "which must secure safe access of the mission to the location of the incident”.Russia has been one of Assad’s key allies in the international arena. Moscow has asserted that the attack was "a homemade rocket loaded with an unidentified chemical agent” and that it was probably a provocation by opposition forces intended to implicate the Syrian president.Earlier, the UN secretary general, Ban Ki-moon, renewed his push for Syria to allow UN inspectors immediate access to the site of the alleged attack."I can think of no good reason why any party, either government or opposition forces – would decline this opportunity to get to the truth of the matter,” he said at a diplomatic forum in Seoul.Syria’s government has offered no public response to UN calls for its team to inspect the site of the attack, in which opponents of Assad said 500 to more than 1,000 people died.The White House has described itself as "appalled” by the reports of the death toll and the US held a flurry of diplomatic talks on Thursday to discuss possible action against the Syrian government.Though it stressed it had still not yet seen conclusive proof of chemical weapon use, the US state department revealed that Kerry had held seven calls with his foreign counterparts on Thursday, and had taken part in a national security council meeting at the White House.The British Foreign Office confirmed that Kerry had spoken to the foreign secretary, William Hague. A spokesman declined to comment on the contents of the call.Washington is split over how to respond to the latest attack. Military leaders such as John Dempsey, the chairman of the joint chiefs of staff, have urged caution for fear of becoming further embroiled in a Middle East conflict when it is unclear whether the rebels would back US interests."Syria today is not about choosing between two sides but rather about choosing one among many sides,” Dempsey said in the letter dated 19 August to Representative Eliot Engel. "It is my belief that the side we choose must be ready to promote their interests and ours when the balance shifts in their favour. Today, they are not.”