Russian President Vladimir Putin told reporters that the agreement envisages a cease-fire that will be effective starting from the start of the day Sunday (21000 GMT or 4 p.M. EST Saturday) as well as a special status for the rebel regions, provisions on border controls and humanitarian issues.
Ukrainian President Petro Poroshenko, however, denied that there was any agreement about autonomy in eastern Ukraine.
Speaking to reporters after the exhausting talks, Putin said "it was not the best night in my life but the morning, I think, it is good because we have managed to agree on the main things despite all the difficulties of the negotiations."
Putin added, however, that he and Poroshenko disagreed on assessing the situation in a key flashpoint, the government- held town of Debaltseve, which has been the focus of fierce fighting for weeks.
Hollande said he and Merkel are committed to helping verify the cease-fire process in Ukraine, along with the Russian and Ukrainian leaders.
Speaking after the talks, Hollande said the announcement of a new cease-fire deal has come as a "relief to Europe."
A previous cease-fire agreed in September fell apart as Ukrainian government forces and Russian-backed rebels both tried to gain more ground.
He also praised Putin for applying "pressure as much as necessary on the separatists."
While the four leaders hailed the agreement, it became immediately clear that Russia and Ukraine continued to disagree on how to end fighting around Debaltseve, a key transport hub between the two main rebel-controlled eastern cities.
