US officials said Clinton tried unsuccessfully to reach Russian Foreign Minister Sergei Lavrov for two days ahead of Tuesday's UN meeting, where Moscow opposed a resolution calling on Syrian President Bashar al-Assad to quit. Asked if Lavrov was refusing to speak to her, Clinton said: "I'm going to be speaking with Sergei Lavrov. He is traveling in Australia." "I've actually traveled in Australia and it's sometimes difficult to make connections. I don't think anyone should read anything into that," Clinton told reporters at the United Nations. The east coasts of Australia and the United States have a time zone difference of 16 hours. State Department spokesman Mark Toner said that Clinton tried in vain for the last two days to call Lavrov, but also said that Deputy Secretary of State William Burns spoke to his Russian counterpart Mikhail Bogdanov about a range of issues, including Syria. Russia, a longstanding ally of Assad, has said that the Security Council does not have authority to force out a country's leader. The draft resolution, backed by the Arab League, calls on Assad to step down ahead of talks on Syria's future. Human rights groups say that Assad's forces have killed more than 5,000 people as they try to crush the latest in a series of uprisings in the Arab world against authoritarian leaders.