U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov resumed negotiations on a Syrian ceasefire plan on Friday, with U.S. officials saying they believed a deal was still possible but warning the talks could not go on for ever.

Senior State Department officials briefing reporters on Kerry’s flight to Switzerland played down the prospect of a final breakthrough on Syria from Friday’s talks, although they said “steady progress” had been made in recent weeks.

“We’ve been taking issues off the table because we’ve reached an understanding on them and continue to have some issues that remain outstanding and that we have been unable to close,” one official said.

Issues still to be resolved were “highly technical and complicated”, the official said. “We can’t guarantee at this point that we are on the cusp of finishing.”

The United States and Russia have backed opposite sides in Syria’s civil war, which shows little sign of ending after 5-1/2 years of violence in which half the pre-war population has been uprooted. Moscow supports President Bashar al-Assad and Washington supports the opposition, saying Assad must go.

Kerry’s meeting with Lavrov is their third in two weeks and they have spoken several times by telephone to try to narrow differences on a Syrian peace plan.

A second U.S. official said that while Kerry would try to make progress, “patience is not infinite” and the United States would not simply keep talking if a conclusion was not reached “relatively soon”.

The officials declined to elaborate on what Washington might do if the talks broke down.

Kerry’s proposal for military cooperation with Russia over Syria has faced strong pushback from U.S. defense and intelligence officials who argue that Moscow cannot be trusted.

The second official said one of the reasons Kerry kept up the effort was because the Syrian opposition supported it as a way to stop the worst violence in their country.

Under the plan being discussed by Kerry and Lavrov, a cessation of hostilities agreement would halt violence between rival forces and open humanitarian corridors.

Russia has insisted that opposition groups separate from al Qaeda linked militants in cities such as Aleppo. Washington wants Assad’s air force grounded to stop its attacks on opposition forces and civilians.

The second U.S. official stressed that any agreement with Russia would have to include an end to the siege by government forces and their militia allies around Aleppo.

“That is still very much the focal point of the conversations we have been having and will be very much an issue (on Friday),” he said.

Kerry and Lavrov had an unwelcome distraction ahead of their talks in Geneva after news that North Korea had conducted its fifth nuclear test, setting off a blast that was more powerful than the bomb dropped on Hiroshima.

Both expressed concerns about North Korea at the start of the meeting.

Source: www.reuters.com