''I believe we have agreed on a big deal,'' President Vladimir Putin said after the drawn-out talks.
"We have managed to agree on the main issues," he added.
''We agreed to a ceasefire starting at 00:00 on February 15.''
''The main thing which has been achieved is that from Saturday into Sunday a general ceasefire should be declared without any conditions,'' confirmed President of Ukraine Petro Poroshenko.
The talks, which were held between the so-called Normandy Four, taking in the presidents of Ukraine, Russia, France and Chancellor of Germany Angela Merkel, came after ten months of conflict in eastern Ukraine.
Over 5000 people have died as a result of the clashes between pro-Russian separatists and the Ukrainian military.
President of France Francois Hollande and Chancellor Merkel said after the talks that they would call on EU member states to back the agreement at a summit later on Thursday.
''There were 16 hours of negotiations in which we had to work hard and in which President Poroshenko did everything, in fact, to achieve a way of stopping the bloodshed - for his country, but also for the civilians and soldiers who live in the areas of Donetsk and Lugansk and suffer the terrible hardship there,'' Merkel said.
''Finally, even President Putin exerted pressure on the separatists, so that they agree that as of midnight on Saturday night or Sunday morning, there is a ceasefire,'' she added.
''I have no illusions, we have no illusions -there is still very, very much work to be done.
''But there is a real chance to change things for the better.''
Ceasefire conditions
As with previous attempts to bring about a ceasefire, conditions include the introduction of special status for the Lugansk and Donetsk regions in eastern Ukraine affected by the conflict.
Legislation must be passed by Kiev on this matter by the close of 2015.
Meanwhile, the agreement also stipulated that all prisoners on both sides must be released.
Heavy weaponry must be withdrawn over a period of no longer than 14 days.
Marcin Wojciechowski, spokesman for Poland's foreign ministry, has siad that ''it is important that the negotiations finished a success, but the key matter will be the implementation of the agreement.'' (nh)
Source: PAP/BBC/Reuters