SHARM EL-SHEIKH: US Secretary of State John Kerry said he would be willing to talk with Syrian President Bashar Assad to stem that nation’s violence.

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

“We have to negotiate in the end,” Kerry said. “And what we’re pushing for is to get him to come and do that, and it may require that there be increased pressure on him of various kinds in order to do that. We’ve made it very clear to people that we are looking at increased steps that can help bring about that pressure.”

Kerry did not elaborate on what that additional pressure would be. There was no immediate reaction in Syrian state media to Kerry’s remarks.

Representatives of the Syrian government took part in talks in Moscow in January with opposition figures, although the main Western-backed opposition group shunned the conference.

Kerry said negotiations are important “because everybody agrees there is no military solution; there’s only a political solution. But to get the Assad regime to negotiate, we’re going to have to make it clear to him that there is a determination by everybody to seek that political outcome and change his calculation about negotiating. That’s underway right now.” Kerry provided no additional details.

He spoke with CBS before leaving Egypt for Lausanne, where he was to resume negotiations with Iran on that country’s nuclear program.

Meanwhile, a monitoring group said on Sunday that more than 215,000 people have been killed in Syria in four years of conflict as the brutal civil war entered its fifth year.

The Britain-based Syrian Observatory for Human Rights said it had documented the deaths of 215,518 people in Syria since March 2011, among them more than 66,000 civilians.

Some 5,000 people have been killed in the past five weeks alone.

The civilian death toll includes 10,808 children, and nearly 7,000 women, according to the group.

While civilians accounted for nearly a third of the deaths, the majority of those killed in the conflict have been combatants.

On the government side, 46,138 soldiers have been killed, along with more than 30,000 Syrian pro-regime militiamen, the Observatory said.

In addition, 3,401 Shiite fighters from abroad have been killed in battle alongside regime forces, among them hundreds from Lebanon’s Hezbollah movement.

On the rebel side, the Observatory gives separate death tolls for fighters from radical and non-radical groups.

It reported the deaths of nearly 27,000 fighters, from the Islamic State group and the Al-Qaeda affiliate Al-Nusra Front.

It said more than 39,000 other rebel fighters had been killed, but included in that figure Kurdish militia killed battling jihadists in the north and east.

It reported the deaths of a further 3,147 people who had not been identified. The fate of many thousands more civilians and fighters from all sides who have been kidnapped also remains unknown.