Senior British and Russian officials are to resume efforts to find a solution to the crisis in Syria, David Cameron and Vladimir Putin have agreed.
The resumption of talks between security advisers was discussed by the leaders in a telephone conversation on Monday, Downing Street said.
President Putin had phoned Mr Cameron to congratulate him on winning the UK election, a spokeswoman added.
They spoke for 30 minutes, with Syria and Ukraine dominating, she added.
“Both leaders agreed that it is in the interest of both the UK and Russia to help find a solution to the civil war in Syria and particularly to stop the rise of ISIL (Islamic State),” the spokeswoman said.
“They agreed that their national security advisers should meet to restart talks on the Syrian conflict.”
The men also agreed both countries should continue dialogue with the “moderate Syrian opposition” in the quest for a solution, Downing Street said.
On Ukraine, the prime minister felt there remained “deep differences” over Russia’s role in the country, the spokeswoman said, “but that the priority now must be to deliver full implementation of the Minsk agreement.”
In February, marathon talks in Minsk resulted in a plan for peace in Ukraine.
The spokeswoman added: “The prime minister concluded the call by noting that the UK and Russia had worked successfully together on the Iranian nuclear issue and he hoped that in the years ahead, we could find other issues where the UK and Russia could work together on matters of mutual interest.”
Russia’s actions in Ukraine and incursions into Western airspace have led to rising tensions with the West.
The conversation came as Russia’s military forces began a large-scale military exercise aimed at testing its combat readiness.
Around 250 aircraft and 12,000 service personnel are involved in the four-day drill, which Russia’s defence ministry called a “massive surprise inspection”.
Cruise missile strikes are expected to take place on practice targets as part of the training exercise.