KIEV (Reuters) - A senior Ukrainian official said on Tuesday his country and Russia had agreed to exchange prisoners from the conflict in eastern Ukraine over the next month.

Kiev’s forces have been battling pro-Russian separatists in the Donbass region of eastern Ukraine since 2014, in a conflict that has claimed more than 13,000 lives. Sporadic fighting continues despite a ceasefire agreement.

In the last prisoner exchange, conducted in December 2017, Ukraine handed over about 300 captives to pro-Russian separatists and took back around 70, but disagreements have prevented any further swaps since then.

“We have agreed to exchange a certain number of our captives during one month,” Vadym Prystaiko, a senior presidential official and the nominee for the post of Ukrainian foreign minister, told reporters.

There was no immediate confirmation from Moscow of the agreement.

“Our task now is to exchange, to return our people home...,” Prystaiko said. He provided no details on the numbers involved or when the process might start.

Russia still holds dozens of Ukrainian captives from the conflict but it is unclear how many Russians are being held in Ukraine.

The ombudsmen of Russia and Ukraine said in Moscow later on Tuesday they were discussing the possibility of the Ukrainian and Russian presidents pardoning some prisoners.

Russia’s President Vladimir Putin and Ukraine’s new leader, Volodymyr Zelenskiy, discussed the issue of prisoner exchanges during their first telephone conversation last week.

Viktor Medvedchuk, a close Kremlin ally in Ukraine, said last week that Kiev and Moscow could swap prisoners within a matter of days, if Ukraine showed sufficient political will.

He said Ukrainian filmmaker Oleg Sentsov, jailed by Moscow on terrorism charges, could be among those exchanged.

“It will require (more) telephone conversations... We are ready to discuss this topic every day if necessary,” said Prystaiko.

He said Putin and Zelenskiy had also discussed during their telephone conversation the plight of 24 sailors captured by the Russian navy in the Kerch Strait last November. Moscow accused them of illegally entering Russian waters, which Kiev denies.