The United States condemned a Syrian army Scud missile attack that killed dozens of people on Friday in the city of Aleppo, and invited the Syrian opposition for talks on finding a negotiated settlement to the conflict.
A State Department statement said the attack on a district of Aleppo and other assaults such as strikes on city blocks and a field hospital were "the latest demonstrations of the Syrian regime's ruthlessness and its lack of compassion for the Syrian people it claims to represent."
The statement, released on Saturday, could help placate the main Syrian opposition grouping, which turned down invitations to visit Washington and Moscow to protest what it described as international silence over the destruction of the historic city of Aleppo by government missile strikes.
Almost two years since the start of the revolt against President Bashar al-Assad, rebels have wrested large swathes of Syria from the control of Assad's forces but the areas remain the target of army artillery, air strikes and, increasingly, missiles.
The decision by the Syrian National Coalition to spurn the invitations and to suspend participation in the Friends of Syria conference of international powers has put peace initiatives on ice.
In the State Department statement, spokeswoman Victoria Nuland said Washington hoped to meet soon with the leadership of the opposition umbrella group "to discuss how the United States and other friends of the Syrian people can do more to help the Syrian people achieve the political transition that they demand and that they deserve."
Invitations from Washington and Moscow had been extended to opposition coalition leader Mouz Alkhatib after he met the Russian and U.S. foreign ministers in Munich earlier this month.
Alkhatib has tried to open channels to Russia and Iran, Assad's only remaining foreign backers, to put pressure on the Syrian strongman to leave power.
Alkhatib, a cleric from Damascus who has said he is morally obliged to try to seek an exit for Assad without more bloodshed, has been criticized by others in the SNC for acting alone.
The rocket attacks on an eastern districts of Aleppo, Syria's industrial and commercial hub, killed at least 29 people on Friday and trapped a family of 10 in the ruins of their home, opposition activists in the city said.
On Tuesday, activists said at least 20 people were killed when a large missile hit the rebel-held district of Jabal Badro, also in the east of the contested city.