U.S. Secretary of State John Kerry says Washington will have to negotiate with Syrian President Bashar al-Assad to end the civil war in Syria.
In an interview broadcast on March 15, Kerry did not repeat the standard U.S. line that Assad had lost all legitimacy and had to go.
"We have to negotiate in the end," Kerry told CBS television. "We've always been willing to negotiate in the context of the Geneva I process," he added, referring to a 2012 conference that called for a negotiated transition to end the conflict.
Those negotiations collapsed after two rounds of talks, and no fresh negotiations have been scheduled since.
"Assad didn't want to negotiate," Kerry said.
Kerry said Washington was working hard to "reignite" efforts to find a political solution to end the war, which is now in its fifth year and has killed at least 215,000 people.
Meanwhile, Syrian activists say government air strikes on a rebel-held area near Damascus have killed at least 26 people, including children, and wounded more than 100.
The British-based Syrian Observatory for Human Rights said the air strikes on March 15 targeted the town of Douma, northwest of the capital.
The monitoring group said the casualties occurred during four air raids.
There was no official comment.
Forces loyal to Assad have in recent months intensified air strikes against rebel-held areas.
Elsewhere, Turkish police said on March 15 that three British male teenagers had been detained and prevented from traveling to Syria.
British police said two are 17 and the third is 19, and that all three are being held by Turkish authorities.
Police said counter-terrorism officers learned on March 13 that the teens had gone missing and were thought to be traveling to Syria. Officers alerted Turkish authorities, who were able to intercept the teenagers, police said.
A number of Britons and other European nationals have traveled to Syria there to join Islamic State extremists, including three British schoolgirls who left their families in London last month.