Russian President Vladimir Putin and Ukrainian President Volodymyr Zelensky agreed Monday to commit to a full and comprehensive implementation of a ceasefire in eastern Ukraine before the end of 2019, according to a joint communique.

Meeting face to face at a four-way summit with the leaders of France and Germany in Paris, all sides also agreed to push for an "all for all" prisoner exchange by the end of the year, but failed to resolve crucial issues such as a timeline on local elections and control of the borders in the rebel-held region.

"The sides commit to a full and comprehensive implementation of the ceasefire, strengthened by the implementation of all necessary ceasefire support measures, before the end of the year 2019," the communique said.

Putin and Zelensky sat down at the French presidential palace along with French President Emmanuel Macron and German Chancellor Angela Merkel for talks focused on reviving a 2015 peace agreement for eastern Ukraine that has largely stalled. The war has killed 14,000 people since 2014, emboldened the Kremlin and reshaped European geopolitics, and Zelensky in particular is keen for it to end.

"We know there are disagreements on the calendar and phasing and we had a long discussion on it, but we said let's give ourselves four months to articulate the security and political conditions for these local elections," Macron told a news conference after the meeting. "We saw the differences today. We didn't find the miracle solution, but we have advanced on it."

Ahead of the meeting, Ukrainian protesters in Kyiv were heaping pressure on Zelensky not to surrender too much to Putin at their first face-to-face meeting.

Ukrainians took part Sunday in a rally in Kyiv ahead of the so-called Normandy format summit in Paris. (Valentyn Ogirenko/Reuters)

But the fact that Putin and Zelensky met at all was a significant step after years of war.

The 2015 peace agreement helped to reduce the intensity of the fighting, but Ukrainian soldiers and Russia-backed separatists have continued to exchange fire across First World War-style trenches along a front line that slices through eastern Ukraine.

Putin said they agreed that there was no alternative to the 2015 accord. He emphasized that Ukraine should quickly extend a law giving wide autonomy to the rebel-held regions in line with the deal and also approve a legislation granting amnesty to the rebels.

He added that in addition to the prisoner swap, agreement was reached to continue pulling back troops in other areas in the east, clear mines there and remove fortifications.

Zelensky acknowledged many previous ceasefire deals didn't hold but he added that "this time we agreed to treat it seriously."

"I'm convinced that if all parties want it strongly, we will be able to implement it," he said.

'No to capitulation!'

While Zelensky still enjoys broad public support, he has been embarrassed by the scandal around his discussions with U.S. President Donald Trump that unleashed an impeachment inquiry. The United States is an important military backer for Ukraine, which is hugely out-gunned by Russia.

While the U.S. was never part of this peace process, U.S. backing has strengthened Ukraine's overall negotiating position vis-a-vis Russia in the past. Now that support is increasingly in doubt, after the Trump administration froze military aid earlier this year and is increasingly focused on Trump's re-election bid. With U.S. influence waning around the world, many in Kyiv see one clear winner: Russia.

Some Ukrainians feared Zelensky would surrender too much to Putin in Monday's meetings, and around 100 opposition activists set up protest tents outside government buildings Monday in the Ukrainian capital, Kyiv. Activists were offering free food in the tents and building a stage in front of Zelensky's office, with banners reading "No to Capitulation!"

"Russia started the war, and any negotiations with the aggressor elicit our suspicion and vigilance, especially when we're being forced into peace on Russian terms," one of the protesters, 21-year-old student Igor Derbunov, told The Associated Press.

The 2015 deal was a diplomatic coup for Russia, ensuring that the rebel regions get a broad authority and resources to survive on their own without cross-border support.

Zelensky wants to tweak the timeline laid out in the accord, which calls for Ukraine to be able to regain control of its border with Russia only after local elections are held in the separatist regions and the regions receive autonomous status. He says Ukraine must get control of its border first before local elections are held, but the Kremlin insists that's not an option.

The summit was the biggest test yet for Zelensky, a comic actor and political novice who won the presidency this year in a landslide — partly on promises to end the war.

Macron praised Zelensky's courage and determination, adding that he made "gestures" that allowed peace talks to be relaunched.

"Today an important step was made. That's the first time in three years such a summit is being held," Macron said. "That's the first time President Zelensky and President Putin are meeting … and we have tangible results."

Prisoner exchange predated talks

Germany and France helped to broker the Minsk accord, in hopes of ending a conflict on Europe's eastern edge that has complicated relations with Russia, a powerful trading partner and diplomatic player. The four countries' leaders held a series of meetings starting in 2014 in Normandy as what is known as the "Normandy format" peace process.

But with progress stalled on the ground, the leaders hadn't met since 2016. Monday's summit was the first involving Zelensky and Macron, who has sought to improve relations with Russia and pushed for the renewed talks, encouraged by Zelensky's determination to end the war.

Ukraine and Russia struck a prisoner exchange deal in September and agreed on a troop pullback from two locations in eastern Ukraine to pave the way for the Paris talks. Russia has also released three Ukrainian navy ships seized a year ago.

An end to the conflict in the region known as the Donbass could also lead to an eventual lifting of EU sanctions against Russia linked to the eastern Ukraine fighting, which the Kremlin and European businesses have pushed for. The EU and U.S. imposed separate sanctions on Russia over its annexation of Ukraine's Crimea.

The EU is expected to extend sanctions this week by another six months. Arriving for meetings in Brussels on Monday, German Foreign Minister Heiko Maas said: "At the moment, I see no grounds to change anything in the European Union's sanctions policy toward Russia in this matter. It would be good if we could get there at some point."

"Everyone knows that a solution to the question of Ukraine is one of the conditions for the relationship between the European Union and Russia developing better ties," he said.