US secretary of state John Kerry sought in a visit to Moscow on Tuesday to make progress in narrowing differences with Russian leader Vladimir Putin over how to end the conflict in Syria.

At the start of a three-hour meeting with Russian foreign minister Sergei Lavrov, Mr Kerry said he wanted to prepare the ground for a third round of talks of world powers on Syria, which is penciled in for Friday in New York. It was unclear whether the meeting would go ahead without progress between Russia and the United States over the role of Syrian President Bashar al-Assad in any political transition and over which rebel groups should be part of peace talks.

Both these issues would be discussed with Mr Putin at the Kremlin later in the day. “I look forward to making real progress,” Mr Kerry said before his meeting with Mr Lavrov, which was followed by a lunch. “I think the world benefits when powerful nations with a long history with each other have the ability to be able to find common ground,” he added.

Mr Kerry told Mr Lavrov: “Even when there have been differences between us we have been able to work effectively on specific issues.” Russia, one of Mr Assad’s staunchest allies, has launched a campaign of airstrikes that it said targeted ISIS militants but which also supported Mr Assad’s forces. The Kremlin says the Syrian people, and not external powers, should decide Mr Assad’s political fate.

Mr Lavrov told Mr Kerry there was a need for more effective international cooperation in fighting terror. “On that route there are still questions which today we need to look at,” Mr Lavrov said in his opening remarks. Mr Kerry described the talks with Mr Lavrov as “good” as he took a break to stroll in a shopping area near the residence of the US ambassador to Moscow where he was mobbed by a crowd who wanted a glimpse of him.

Asked whether the New York meeting would happen, Mr Kerry said: “I need to meet with the president (Putin). I look forward to that. It will be an important meeting.” The run-up to the Moscow talks underlined the distance between Moscow and Washington on how to deal with the Syria crisis.