The Ukrainian government exchanged 200 prisoners with pro-Russian separatists in the embattled eastern region of the country on Sunday afternoon — a move experts say represents a step toward peaceful relations between Ukraine and Russia, which have been locked in a conflict for more than five years.

The prisoner swap was agreed upon earlier this month in Paris during the first face-to-face talks between Ukrainian President Volodymyr Zelensky and Russian President Vladimir Putin, a meeting that was mediated by French President Emmanuel Macron and German Chancellor Angela Merkel.

“The swap is a big deal in the context of Ukraine-Russia relations and the ongoing war,” Christopher Miller, a Kyiv-based journalist, told Vox. “Momentum for solving the war had stalled for nearly three years under Ukraine’s previous president, Petro Poroshenko. Peace talks between Kiev and Moscow were revived after Zelensky was elected.”

This prisoner exchange, which comes after a previous swap of dozens of prisoners earlier in September, saw each side release all of the prisoners it had, and symbolizes a tentative advancement in those peace talks.

The trade of prisoners took place at a checkpoint close to the industrial town of Horlivka in the eastern Donetsk region of Ukraine. Many of the captives carried their possessions in plastic bags and met tearful family members as they got off buses.

Ukraine and pro-Russian separatists completed an all-for-all prisoner swap in the breakaway Donbass region as the two sides push for the implementation of a 2014 peace deal https://t.co/veL28BQ6WC pic.twitter.com/6DSp59FBy7 — Reuters (@Reuters) December 29, 2019

One woman being returned by the pro-Russian separatists had the message “My country is Ukraine!” hand-written onto her clothing as she walked off her bus.

Ukraine’s presidential office live-streamed footage of the swap online, and is likely to hail the move as evidence that Zelensky is making positive progress toward achieving his promise of moving Ukraine toward peace with Russia, as he pledged to do before winning a landslide victory in April.

But not everyone in Ukraine was happy about the swap. More nationalist-minded Ukrainians are protesting the fact that Kyiv handed over five riot police officers who shot at demonstrators in 2014 during protests against then-President Viktor Yanukovych’s pro-Russian policies.

Critics of the swap argued the officers should have remained in custody until they could be tried for the deaths of more than 100 protesters. The Ukrainian government has promised those officers will still face the courts, and that they will be required to cooperate with law enforcement officials despite their release.

Despite the move being somewhat controversial within Ukraine, European leaders said they see the captive exchange as a step toward peace.

“The prisoner swap that was completed today is a long-awaited humanitarian measure,” Macron and Merkel said in a joint statement. “In line with the decisions taken at the Paris summit, it must now be followed by the full implementation of the ceasefire.”

Ukraine and Russia had agreed to a full ceasefire by the end of 2019 at the Putin-Zelensky summit; thus far, that has not come to pass. The two nations have fought over Russian annexation of the Ukrainian territory of Crimea since 2014, when Russia began to back pro-Russian separatist rebels in Ukraine. The fighting has killed more than 14,000 people, making it the bloodiest European conflict since the Balkan war.

Zelensky hoped for President Trump’s support in dealing with Russia, but hasn’t gotten it

Ending the conflict is not expected to be easy for Zelensky. Russia has far greater military resources, and Putin is an aggressive negotiator who is always angling to expand Russian influence in the region.

And complicating things further are Zelensky’s ties to the US impeachment saga.

Earlier this year, President Donald Trump attempted to make military aid Ukraine relies on to combat Russia conditional on whether Zelensky agreed to Trump’s demands to launch an investigation into former Vice President Joe Biden. That aid was eventually released, but Zelensky has yet to obtain a key White House meeting he has repeatedly asked Trump for. Such a meeting would signal to Russia that Washington is firmly behind Kyiv — and the fact that it hasn’t happened has weakened Zelensky’s negotiating position with Putin, experts say.

Lacking that meeting — and any public gestures on behalf of Ukraine by the US president — Zelensky has had to find other ways to advance peace, including working with EU allies like France and Germany. While the prisoner exchange did not mark the end of the conflict, for now, it would seem that things are moving in the direction of stability.