Russian Foreign Minister Sergei Lavrov said on Tuesday he was amazed by the hullabaloo over his failure to discuss a UN Syria resolution with US State Secretary Hillary Clinton.

Clinton tried to reach Lavrov by telephone for about 24 hours but he was "apparently unavailable" while on visit to Australia, State Department spokeswoman Victoria Nuland said.

Lavrov said he was busy negotiating with his Australian partners, adding that he and Clinton would talk later.

“We will talk as soon as there is an opportunity. Although it is ineffective to discuss an important problem such as the situation in Syria from another end of the world, there are UN ambassadors for that.”

Lavrov also added that he will not persuade Assad to resign and that "regime change is not our job."

However, he dismissed the view that Russia will support Assad no matter what.

“We’re not President Assad’s friends or allies,” he said.

A number of Western countries have been trying to persuade Moscow to support a draft resolution providing for President Bashar Assad’s resignation and effectively giving the go-ahead to a military operation in the country.

"The longer the Assad regime continues its attacks on the Syrian people and stands in the way of a peaceful transition, the greater the concern that instability will escalate and spill over throughout the region," Clinton said.

Russia has been one of Assad’s staunchest supporters during the ten-month-long uprising against his regime. Moscow has proposed its own draft UN resolution on Syria, but Western members of the Security Council have criticized it for being too soft.

At least 5,400 people have been killed in the government's 10-month crackdown on protesters, according to the UN. Syrian authorities blame the violence on armed gangs affiliated with al-Qaeda and say more than 2,000 soldiers and police have been killed.