Putin says finalising 'large-scale' prisoner swap with Ukraine

Russian President Vladimir Putin on Thursday said Moscow was completing negotiations on a "large-scale" prisoner swap with Kiev, in what could be a step towards easing tensions between the neighbours.

Putin's first comments on the long-reported exchange came as a Ukrainian court released a former pro-Russian separatist suspected of involvement in the downing of flight MH17.

"We're reaching the final stage of talks on the swap... it will be large-scale," Putin told an economic forum in the Russian city of Vladivostok, adding that the date of the exchange would soon be announced.

He said a swap would be "a huge step towards normalising relations".

Better ties were "inevitable" because Russia and Ukraine are "two sides of the same people," he added.

The Russian side found it difficult to agree to the names Ukraine had put forward for the swap, the president added, without providing details of any decisions.

Meanwhile in Kiev, Vladimir Tsemakh's release from pre-trial detention sparked speculation he would be used as part of the swap despite his alleged role in the downing of MH17.

The Kremlin has demanded that Tsemakh is on the list of prisoners to be exchanged, according to Russian and Ukrainian media reports.

Tsemakh is a Ukrainian who is believed to have been in charge of an air defence unit in the forces of the separatist Donetsk People's Republic near Snizhne in eastern Ukraine.

This is where Malaysia Airlines flight MH17 came down in 2014, killing 298 people, most of them Dutch citizens.

European lawmakers describe Tsemakh as a "key suspect" and have asked Kiev to keep him available for testimony in the probe.

Dutch MEP Kati Piri on Wednesday said demanding the exchange of Tsemakh was a "strange request" which "suggests that the Russian government wants to prevent this suspect from appearing in court".

Last week Ukraine released Russian state media journalist Kyrylo Vyshynsky, who had been in custody for more than a year, pending a trial for "high treason".

Ukraine's new President Volodymyr Zelensky offered to hand Vyshynsky over to Moscow in exchange for Ukrainian film director Oleg Sentsov, who is a prisoner in a penal colony in the Russian Arctic.

But Zelensky, whose election earlier this year raised hopes of an easing of tensions with Russia, declined to comment on whether the director would be part of any swap.

Sentsov, 43, has become Ukraine's most famous political prisoner. He was arrested in 2014 and is serving a 20-year sentence for planning "terrorist attacks" in Crimea.

Among other prisoners who could be eligible for an exchange are 24 Ukrainian sailors captured last year.

Russia has been holding the sailors since seizing their three vessels off Crimea last November, in the most dangerous direct clash between Russia and Ukraine in years.

Some 13,000 people have been killed in Ukraine's conflict with Russian-backed separatists in eastern Ukraine, which broke out shortly after Moscow annexed Crimea in 2014.