The Russian and U.S. presidents, Vladimir Putin and Barack Obama, have spoken by telephone about preparations for the UN-backed Syrian peace conference that is due to begin in Switzerland on January 22.
The White House said in a statement on January 21 that Obama and Putin also discussed the ongoing international program to remove and destroy Syria's chemical weapons.
The White House statement says they talked about cooperation in the P5+1 process on Iran's nuclear program, as well as potential security cooperation during the Winter Olympics in Sochi, Russia during February.
The Kremlin did not release any details about the content of the telephone conversation, but described it as businesslike and constructive.
Russia supports the Syrian government while Washington backs Syria's moderate rebels. But the two powers have jointly pressured Syria's warring parties to pursue negotiations.
Delegates from some 40 countries are expected to attend the talks that start in the Swiss city of Montreux.
Extremist Islamists and militants linked to Al-Qaeda have not been invited to the talks.
On January 21, Iran -- a leading ally of the Syrian regime -- said it expected the talks to fail.
That statement from Tehran came after UN Secretary-General Ban Ki-moon withdrew an invitation for Iran to attend the meeting.
The United States and other Syrian opposition supporters had argued against Iran's participation.
With reporting by Reuters and ITAR-TASS.