The deal was declared on Monday, December 9, 2019, in a joint communiqué issued by the four leaders after a summit in Paris, presstv reported.
"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," said the final communiqué.
The summit, brokered by the French and German leaders, will result in the release and exchange of all "conflict-related detainees" by the end of the year.
The two sides also pledged to disengage military forces in three additional regions of Ukraine by the end of March 2020, without specifying which regions would be affected.
Russian President Vladimir Putin later hailed the summit as an "important step" toward a de-escalation of the conflict. However, he said the agreement must be coupled with changes to the Ukraine Constitution.
"The process of achieving ceasefire needs to be synchronized with the implementation of political reforms in Ukraine, envisaged in the Minsk agreements. In the first place, this means introducing changes to the country's constitution, which give Donbass (Donetsk and Luhansk regions) a permanent special status,” he noted.
Putin also noted he needed more points of passage between front lines in Eastern Ukraine for civilians and the implementation of an amnesty for people involved in the conflict.
"An important point - the number of checkpoints at the contact line needs to be increased, the most comfortable conditions need to be created for hundreds and thousands of local residents to go through the checks the fastest way without many-hour lines," he said.
In a news conference after the summit, Ukrainian President Volodymyr Zelensky said no compromise was possible with concession of territory, including Donbass and Crimea.
A Kremlin spokesman had earlier said that the Russian side does not consider it possible to discuss Crimea in any format.
Zelensky also said a new exchange of prisoners would take place between Ukraine and pro-Moscow separatists by the end of the year.
French President Emmanuel Macron said Russia, Ukraine, France and Germany are to hold a new Ukraine summit in 4 months to take stock of progress on ending the conflict.
German Chancellor Angela Merkel also said she is “very pleased” with the Monday talks, and that there is good will from the talks on Ukraine to address difficult issues.
Five-and-a-half years of fighting between Ukrainian government forces and Russian-backed rebels have cost 13,000 lives.
Pro-Russian separatists seized control of large swathes of Donetsk and Luhansk regions in April 2014, just after Russia's annexation of Ukraine's Crimea peninsula.
It was an insurgency against the new pro-Western authorities in the capital Kyiv, who had ousted the pro-Russian President, Viktor Yanukovych, in street protests dubbed the "Maidan Revolution".
The separatists later declared independence from Ukraine - but no country has recognized their "republics". ■
The Polish government has vowed to seek support for its proposal to have the European Union reinstate permits for Ukrainian haulers, but the bloc's executive has declared that the return of permits is not possible, according to news reports.