Senior British and Russian officials are to meet to resume efforts to find a solution to the Syria crisis, David Cameron and Vladimir Putin have agreed.

Downing Street said the resumption of direct talks between the two leaders' national security advisers was discussed when the Russian president called the Prime Minister to congratulate him on his re-election.

The pair were said to have spoken for 30 minutes, with discussions centred on efforts to halt the rise of Islamic State in the chaos of the Syrian civil war - in which Moscow is a key figure as an ally of the Damascus regime of Bashar Assad - and on Ukraine.

"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," a spokeswoman said.

"They agreed that their national security advisers should meet to restart talks on the Syrian conflict. The Prime Minister reiterated his belief that President Assad could not be part of the solution in Syria. And they agreed that both countries should continue talks with the moderate Syrian opposition as part of this effort."

On Ukraine, the PM said there remained "deep differences" over Russia's role in the instability of its neighbour "but that the priority now must be to deliver full implementation of the Minsk agreement.

"The Prime Minister emphasised the need for the trilateral contact group to continue to meet and to work through the outstanding issues.

"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."