US Secretary of State John Kerry and his Russian counterpart Sergei Lavrov spent nearly half an hour on the phone Sunday morning discussing the crises in Syria and North Korea, DPA reported.
Washington has lent increasing support to the coalition of rebel groups who are trying to bring down al-Assad.
State Department spokeswoman Victoria Nuland said the two men agreed to set up their first bilateral meeting since Kerry replaced Hillary Rodham Clinton as the top US diplomat.
"On Syria, they discussed the importance of the US and Russia using their respective influence on the parties in support of a viable political transition process," Nuland said.
She said Kerry emphasized the urgency of ending bloodshed in Syria, where more than 70,000 civilians have been killed in two years of civil conflict, and of helping Syrians "resist extremism."
A United Nations panel is to issue a report on Monday to update the Syrian human rights situation. Just days ago, Kerry said the death toll could be as high as 90,000, citing his Saudi Arabian counterpart.
Kerry and Lavrov agreed that close cooperation on North Korea's recent detonation of another nuclear bomb was needed at the UN Security Council to enact a "swift response" to Pyongyang's "latest provocative step," Nuland said.
European Union foreign ministers are set Monday to debate Syria, with disagreements remaining on how to proceed with the bloc's arms embargo upon the opposition ahead of the embargo's March 1 expiration date.
Britain is pushing hard to lift the embargo, insisting that such a step would not translate into weapon deliveries, EU diplomats said.
Others worry about fueling Syria's nearly two-year conflict.
If there is no deal by March 1, all of the EU's sanctions on Syria will be lifted.
However, diplomats ruled out the possibility of the showdown over the arms embargo going that far.