The leaders of Ukraine, Russia, Germany and France are meeting in Paris to find a way to end the war in eastern Ukraine.
A series of meetings are being held at the Elysee presidential palace to try to revive a 2015 peace deal that has been largely ignored.
In the years since, 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.
A major breakthrough at the summit is unlikely, and Ukrainian protesters in Kiev are heaping pressure on Ukrainian President Volodymyr Zelenskiy not to surrender too much to Russian President Vladimir Putin at their first face-to-face meeting.
Whatever happens, the summit is the biggest test yet for Mr Zelenskiy, a comic actor and political novice who won the presidency this year in a landslide – partly on promises to end the war.
While Mr Zelenskiy still enjoys broad public support, he has been embarrassed by the scandal around his discussions with US President Donald Trump that unleashed an impeachment inquiry. The US is an important military backer for Ukraine, which is hugely out-gunned by Russia.
Some Ukrainians fear Mr Zelenskiy will be outmanoeuvred by Mr Putin in Monday’s meeting.
Around 100 opposition activists have set up protest tents outside government buildings in the Ukrainian capital of Kiev. Activists are offering free food in the tents and building a stage in front of Mr Zelenskiy’s office, with banners reading “No to capitulation”.
In front of the French presidential palace, two protesters from the feminist group Femen, which originated in Ukraine, bared their breasts and shouted “Stop Putin Now!”. They were quickly whisked away by police.
Russia wants to use the summit to increase pressure on Mr Zelenskiy to fulfil the 2015 Minsk peace accord, which gives the rebel-held regions more autonomy in exchange for ending the fighting.
Mr Zelenskiy wants to tweak the timeline laid out in the Minsk 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. Mr Zelenskiy says Ukraine must get control of its border first before local elections are held.
The Kremlin insists that is not an option, and the separatists hope that Russia, France and Germany refuse Mr Zelenskiy’s requests.
French officials say potential changes to the timeline will be discussed, but stressed that the summit is aimed at fulfilling the Minsk accord – not writing a new peace deal.
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.
But with progress stalled on the ground, the leaders have not met since 2016. The summit is the first involving Mr Zelenskiy and French President Emmanuel Macron, who has sought to improve relations with Russia.