US Secretary of State Hillary Clinton called on Russia and China Tuesday to be "part of the solution" to the crisis in Syria and warned that any hope for peace depended on a political transition.

“We believe there is a way forward and we are ready to pursue that. And we invite the Russians and the Chinese to be part of the solution,” she said at a news conference in the Georgian Black Sea city.

She spoke after Russia’s President Vladimir Putin and China’s President Hu Jintao agreed at a meeting in Beijing that they would work together more closely at the United Nations.

Russia and China, veto-wielding members of the UN Security Council, have resisted every attempt to impose sanctions against the Syrian regime even after a massacre of more than 100 people last month in violation of a UN peace plan.

Hu said the two giant neighbours could together “set the global political and economic order in a more fair and rational direction.”

The combination appeared to be a setback for Clinton’s efforts to get international backing for a political transition in Syria, ultimately including the removal of Syrian President Bashar al-Assad.

She is meeting on Wednesday in Istanbul with leaders from European powers and regional states that are increasingly fearful of a descent into all-out civil war in Syria, with destabilising dangers for its neighbours.

“I think it is pretty clear we all have to speed up our efforts to intensify the political transition, and that has to be the main focus of our diplomacy and our work, both with each other, within the international community, the United Nations,” she said.

Clinton said it was clear that after the massacre in Houla last month “peace and human dignity will not be possible in Syria without political change.”