British Prime Minister David Cameron visits Russian President Vladimir Putin Friday for talks aimed at ending Syria's two-year-long civil war.
Cameron's meeting with President Vladimir Putin in the Black Sea resort city of Sochi comes amid a renewed international push for a resolution to the conflict that has killed at least 70,000 people.
Washington and Moscow this week agreed to call an international conference later this month to press for peace talks between the Syrian government and rebels fighting to oust President Bashar al-Assad, a longtime Russian ally.
There has been speculation that London may be interested in hosting the conference.
U.S. Secretary of State John Kerry on Thursday renewed his call for Assad to step down, saying he cannot be a part of a transitional government to lead Syria out of its crisis.
The statement appears to clarify the U.S. position.
On Tuesday, Kerry had said it is "impossible" for him as an "individual" to see President Assad governing Syria in the future, but he added that the Syrian president's fate is not for him to decide.
Meanwhile, clashes continued to break out across Syria. The Local Coordination Committees, an opposition activist group, said at least 22 people were killed in fighting early Friday in the capital of Damascus and the central city of Homs, as well as Aleppo, Hama, and Daraa.
Photo Gallery: Latest Images from Syria
Rebel fighters of the Syrian Kurdish Popular Protection Units (YPG) talk in the Sheikh Maqsoud neighborhood of Aleppo, May 9, 2013.
A view shows damaged buildings and debris in the Khaldiyeh district of Homs, May 9, 2013.
Syrian children play near a water distribution point in the Almyassar central district of Aleppo, May 8, 2013.
A Free Syrian Army fighter holds his weapon in Raqqa province, east Syria, May 6, 2013.
A Free Syrian Army fighter stands behind a pile of sandbags in Raqqa province, east Syria, May 6, 2013.
Free Syrian Army fighters prepare to head toward the front line in the al-Ziyabiya area, Damascus, May 5, 2013.
An armored vehicle is seen parked as Free Syrian Army fighters gather on a street in the refugee camp of Yarmouk, near Damascus, May 5, 2013.
This image taken from video obtained from the Ugarit News shows smoke and fire filling the the skyline after an Israeli airstrike, Damascus, May 5, 2013.
This photo released by the Syrian official news agency SANA shows damaged buildings wrecked by an Israeli airstrike in Damascus, May 5, 2013.
This image provided by ENN shows a protester with a sign reading "If America does not know who used the chemical weapons, so it could be flying saucers from another planet," Sarmada, Idlib, Syria, May 3, 2013.
A man reacts after his grandson was injured during what activists said was shelling by forces loyal to Syrian President Bashar al-Assad, Raqqa province, Syria, May 2, 2013.
Residents inspect a damaged building that was shelled by forces activists say were loyal to Syrian President Bashar al-Assad, Raqqa province, Syria, May 2, 2013.
This photo released by the Syrian official news agency SANA shows Syrian President Bashar al-Assad visiting the Umayyad Electrical Station, Damascus, Syria, May 1, 2013.