Secretary of State John F. Kerry said Sunday that he and his Russian counterpart had reached a “provisional agreement in principle” for a temporary truce in the Syrian civil war and that it could start within days.

Kerry said he spoke Sunday morning to Russian Foreign Minister Sergei Lavrov for the second day in a row, adding that final details are to be ironed out in a phone call between President Obama and Russian President Vladimir Putin. Among the unsettled issues are how a cease-fire would be enforced and how breaches would be resolved.

Kerry said he believes that a cessation of hostilities “could begin in the coming days.”

While he did not elaborate on the parameters of a cease-fire, the secretary said it will be up to Russia to get Syrian President Bashar al-Assad and Iran to agree to the conditions and up to the United States to enlist the acquiescence of the major opposition groups and other members of a multinational group pushing peace talks. After that, he said, a temporary cease-fire could be implemented.

In an interview with Spanish newspaper El Pais, Syrian President Bashar al-Assad said he’d be open to a cease-fire under certain conditions. (AP)

“We are giving life to what was promised in Munich,” Kerry told reporters in a short news conference in the Jordanian capital, referring to a Feb. 12 agreement for a “cessation of hostilities” within a week, a deadline that came and went Friday. “We are filling out the details.”

It is not clear whether either the Syrian government or the opposition will join a cease-fire. Both have expressed a willingness to take part, but they have set preconditions that may prove difficult to meet.

The opposition groups said this weekend that they would agree to a temporary truce if Russia, Iran and various militias stop attacking them. They also have demanded a halt to attacks on Jabhat al-Nusra, also known as the al-Nusra Front, which the United Nations and the United States consider a terrorist group that should be excluded from any cease-fire.

Assad said in an interview published in the Spanish newspaper El País that he is also open to a cease-fire as long as the “terrorist” opposition groups fighting to end his rule do not use a lull in fighting to gain advantage.

Kerry acknowledged that the warring sides face a difficult decision on whether to take part in a truce.

“We are clear: If you don’t choose to be part of it, then you are choosing to perhaps make yourself a target,” he said. “There’s a stark choice for everybody here.”

It is also unclear whether Russia is prepared to stop air assaults that have supported Syrian government advances on rebel strongholds. The State Department has criticized the attacks as indiscriminate and the cause of many civilian casualties. Kerry said he had again urged Lavrov to have Russia halt its military campaign against opposition positions.

“Does the bombing have an impact?” Kerry asked rhetorically. “Of course it does. This morning, Foreign Minister Lavrov and I talked about speeding up the process to try to reduce that as soon as possible.”

But Kerry sounded a note of optimism that an end to the fighting is possible.

“We are in fact making progress even as I stand here today,” he said. “We are closer to a cease-fire today than we have been.”

Kerry also went to the Amman home of Palestinian leader Mahmoud Abbas to discuss tensions between Israelis and Palestinians. He has been working for months to curb the violence that ignited last fall amid false rumors about Israel’s intentions concerning a compound in Jerusalem that is revered by Jews and Muslims.

He then met in Aqaba with Jordan’s King Abdullah II. Kerry’s office said other officials also attended the meeting, including Frank Lowenstein, the State Department’s point man on Israeli-
Palestinian relations. It was not immediately clear who the other officials were.

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