MOSCOW - Russian President Vladimir Putin and his Ukrainian counterpart, Volodymyr Zelenskiy, on Friday held their first talks since the election of the Ukraine president last April - a 20-minute phone call noteworthy for its implications regarding efforts to end the simmering war between Kyiv and pro-Russian separatists in Ukraine's east.

Kremlin spokesman Dmitry Peskov was quick to point out that Ukraine had initiated the call, in which Zelenskiy and Putin discussed a stalled peace agreement for Ukraine's Donbas region, as well as the possibility of prisoner exchanges "from both sides."

A Ukrainian presidential spokesman was even more expansive, saying Zelenskiy had raised the issue of an exchange for 24 Ukrainian sailors captured at sea by Russia last November.

Russia is holding dozens of Ukrainian citizens whom human rights groups have labeled prisoners of conscience. Ukraine also has sentenced several Russians to lengthy prison sentences for joining with armed Moscow-backed separatists fighting in Ukraine's east.

New president, new rules

The election of Zelenskiy, an actor with no prior political experience, but who played the role of Ukraine's president in a popular television sitcom, seemed initially to offer hope for progress toward resolving the Ukraine conflict.

Putin has expressed disdain - openly and often -for Zelenskiy's predecessor, Petro Poroshenko. Moreover, Zelenskiy won a landslide victory over Poroshenko by campaigning on a promise to find a peaceful solution to the war.

Yet hopes for a reset in relations quickly faded.

The Russian leader refused to congratulate Zelenskiy on his election victory. Soon afterward, Putin signed an order streamlining procedures for Ukrainians in separatist-controlled regions of east Ukraine to receive Russian passports - a move denounced as provocative by Ukraine and Western powers.

Furthermore, the Russian leader, in power for nearly two decades, has occasionally taken pleasure in highlighting the new Ukrainian leader's inexperience.

"Everything he said was talented and funny," said Putin during a nationally televised call-in program while speaking of having seen Zelenskiy perform as a comedic actor in the early 2000s.

"What's happening now is not funny," added Putin.

New push for peace?

After five years, the war in east Ukraine has left more than 13,000 dead and thousands more displaced.

A cease-fire brokered with support from Germany and France in 2015 - the so-called Minsk peace accord - ended widespread fighting but has not stopped the drip of near-daily casualties.

Earlier this month, Zelenskiy issued an online video appeal proposing that U.S. President Donald Trump and the British prime minister join in a new round of negotiations with Russia aimed at finding a diplomatic solution to the war. The Kremlin says it is considering the suggestion.

Yet it's far from clear how the two sides can move past fundamental differences.

Russia continues to maintain it is not a participant in the war - insisting Russians fighting in the Donbas region are merely impassioned "volunteers" seeking to protect Russian-speakers from the threat of Ukrainian nationalists.

Western journalists have documented Russia's hybrid presence in the Donbas, which includes active Russian army servicemen sent on instructions from Moscow.

Crimea issue

Then there is Russia's annexation of the Crimean Peninsula from Ukraine in 2014.

While the Kremlin insists Crimea's "reunification" with Russia is irreversible, Ukraine and Western powers long ago imposed sanctions that they insist will remain until the territory is wrested from Russian control.

In a reminder of Russia's continued sensitivity to the Crimea issue, over 50 Crimean Tatars - a predominantly Muslim group that makes up 15% of Crimea's population - were arrested in Moscow this week for protesting what they said was persecution of the community for its opposition to Russian rule.

Russia has sentenced several members of the group on terrorism charges, alleging that they had ties to the banned Islamic organization Hizb ut-Tahrir.

But for all the complexities in the Russian-Ukrainian relationship, Kremlin spokesman Peskov insisted Putin had a diplomatic knack for finding the right thing to say, even to perceived adversaries like Zelenskiy.

In this case, said Peskov, it was one simple word from the Russian leader.

"Hello."