Syria conflict: US wants to 're-ignite' peace talks, says Kerry
Speaking as the war enters its fifth year, Mr Kerry said it was "one of the worst tragedies any of us have seen".
He said the international community was upping pressure on Syria's regime to hold new peace talks, saying "we have to negotiate in the end" with Mr Assad.
More than 215,000 people are estimated to have been killed in the conflict.
"We are working very hard with other interested parties to see if we can re-ignite a diplomatic outcome," Mr Kerry said in an interview in the Egyptian resort of Sharm el-Sheikh.
'No military solution'
He told CBS News the US was working with the moderate opposition in Syria as well as pursuing a diplomatic track with "a number of different critical players in this tragedy".
"Everybody agrees there is no military solution; there's only a political solution," he said.
The US has "always been willing to negotiate in the context of the Geneva I process," he added, referring to a 2012 plan to end the conflict that included forming a transitional governing body and holding free and fair elections in Syria.
The White House has in the past insisted that Mr Assad stand down as part of a political settlement.
Some analysts suggested that Mr Kerry's comments marked a shift in US policy, but State Department spokeswoman Marie Harf denied this.
She said Mr Kerry had merely repeated the "long-standing policy" that the US wanted negotiations with the regime at the table - but not direct talks with President Assad.
"Policy remains [the] same and is clear: there's no future for Assad in Syria," she tweeted.
BBC
