Ukrainian President Volodymyr Zelensky and Russian leader Vladimir Putin have discussed a potential new prisoner exchange amid a fresh push to de-escalate the five-year conflict, Kiev said on Friday.

The two leaders focussed on preparations for a new meeting after they met for the first time for a Western-mediated summit in Paris in December and agreed measures to help end an ongoing conflict.

"Volodymyr Zelensky and Vladimir Putin paid special attention to the process of releasing Ukrainian citizens being held" in Russia, Crimea and separatist-controlled regions of Ukraine, the statement added.

The two leaders agreed to ramp up work of negotiators to implement the existing agreements, Kiev said.

There was no immediate statement from the Kremlin following the phone call.

Zelensky, a 41-year-old comedian with no previous political experience, won a landslide victory last year on pledges to end the conflict in eastern Ukraine and improve ties with Russia.

He managed to negotiate a long-awaited swap with Russia that saw the two countries exchange a total of 70 prisoners in September.

Zelensky and Putin last spoke by phone on December 31.

The Kremlin announced this week it had appointed a new pointman for Ukraine who is seen as a less divisive figure than his predecessor and could herald a new phase in the talks, a French presidential official has said.

Ties between Ukraine and Russia were shredded after a bloody uprising ousted a Kremlin-backed regime in 2014. 

Moscow went on to annex Crimea and support insurgents in eastern Ukraine. More than 13,000 people have been killed in the conflict, Europe's only active war.