PARIS — The United States, France, and Russia must step up their coordination in striking the Islamic State in Syria after the Paris terrorist attacks, Secretary of State John Kerry said on Tuesday, but he insisted that cooperation cannot begin until there is a cease-fire and a political transition.

Kerry expressed optimism that a shift in Syria could come within weeks now that the United States and more than a dozen other nations, including Iran and Saudi Arabia, have agreed to a framework to end the crisis there.

That will depend, he said, on the ability of Syrian opposition groups to organize and negotiate with the government of President Bashar Assad, and cooperation from Russia and Iran to ease the transition.


"Now, all we need is the beginning of the political process, and the cease-fire goes in place — that's a gigantic step," he said in an interview with reporters who were traveling with him.

Kerry also met with President François Hollande of France on Tuesday to discuss how to intensify pressure against the Islamic State, also known as ISIS, ISIL, or the Arabic acronym Daesh.

"If we can get that done, that opens up the aperture for a whole bunch of things," Kerry said of a cease-fire in the four-year civil war. "So we're weeks away, conceivably, from the possibility of a big transition for Syria."

The more quickly the political changes occur, he added, "the faster the violence can taper down and we can isolate Daesh and al Nusra, and begin to do what our strategy has always set out to do."

Once the political process is on track, Kerry said, the United States and Russia could begin to "cooperate on the broader scale, which we can't do until we have some definition."

Although the United States has said Assad must leave office as part of any solution to the conflict in Syria, he has the support of Russia and Iran.


But Kerry said on Tuesday that it would be impossible to defeat the Islamic State without the departure of Assad.

"He's complicit in the rise of Daesh, and therefore, as long as Assad is there, you cannot fully go get rid of this phenomenon," Kerry said.