U.S. Secretary of State John Kerry says he would be willing to talk with Syrian President Bashar Assad to stem that nation's violence.

In an interview with CBS News, Kerry says the U.S. is pushing for Assad to seriously discuss a transition strategy to quell the Arab country's four-year civil war.

Kerry says, "We have to negotiate in the end."

While previous efforts saw Assad's government not engage on a concrete plan, Kerry says the U.S. is trying "to get him to come and do that."

He says that may require additional pressure on Assad's Iran-backed government, which is fighting Sunni rebels and Islamic State extremists.