Russian President Vladimir Putin and Ukrainian leader Volodymyr Zelenskiy met for the first time on Monday in Paris, and agreed to a full ceasefire in eastern Ukraine before the end of the year.
The two leaders also agreed that an exchange of prisoners would take place before next year.
Mr Putin and Mr Zelenskiy met for talks on the devastating five-year conflict in eastern Ukraine, which were mediated by France and Germany.
French President Emmanuel Macron, who has advocated opening up to Russia, and German Chancellor Angela Merkel were at the talks, which took place at the Presidential Palace.
"The sides commit to a full and comprehensive implementation of the ceasefire, strengthened by the implementation of all necessary support measures, before the end of the year 2019," a summit communique said.
Mr Putin and Mr Zelenskiy also pledged to disengage military in three regions of Ukraine by the end of March. The regions were not disclosed.
Since 2014, 14,000 people have been killed in a war between Ukraine and pro-Russian separatists. The conflict has left an indelible mark on European politics.
The summit marked a major test for Mr Zelenskiy, a political newcomer and comic who became president this year after promising to end the war.
Despite the promises made by the leaders, the two sides still disagree on issues such as withdrawal of Russia-backed troops and local elections in parts of the Ukraine held by separatists.
Mr Zelenskiy said that his country wouldn't make any concessions on territory in exchange for a ceasefire, indicating that Monday's agreement was a fragile one.
The annexation of Crimea, which led to international sanctions against Russia, was not on the table during the discussions.
"We saw differences today," said French President Emmanuel Macron, who hosted the talks with German Chancellor Angela Merkel.
"We didn't find the miracle solution but we have advanced on it."
Mrs Merkel was more optimistic than Mr Macron. She hailed the "good-will" of both leaders but warned that there still plenty of work to do to achieve peace.
"I say very openly we have a lot of work to do, but my feeling from this meeting here today is that there is good-will to resolve difficult questions," she said alongside the other three leaders.
"I am very pleased with the meeting."
Further talks to review the progress of the ceasefire will be held in four months.
Mr Zelenskiy wants to tweak the timeline in the 2015 Minsk accord, which calls for Ukraine to regain control of its border with Russia only after local elections are held in the separatist regions, and that the regions receive autonomous status.
He said Ukraine must get control of its border before local elections are held but Russia has rejected this.
Russia wanted to use the summit to increase pressure on Mr Zelenskiy to fulfil the Minsk peace accord.
Germany’s Foreign Minister, Heiko Maas, praised Mr Zelenskiy and said he had brought “new momentum”,
But Mr Maas said that Russia “needs to make a move too”.