The leaders of Russia, Ukraine, France and Germany have reached a ceasefire deal after 17 hours of talks in Minsk, Belarus, on the Ukrainian conflict.
The ceasefire will come into force on Sunday as part of a deal that also involves the withdrawal of heavy weapons from the front line.
The deal was reportedly also signed by the self-proclaimed leaders of the pro-Russian separatists in Ukraine's Luhansk and Donetsk regions.
Poroshenko said the document does not give any autonomy to the regions held by separatists and also envisages Ukraine reestablishing control over its borders by the end of 2015.
The agreement also calls for the withdrawal of all foreign forces from Ukrainian territory.
Poroshenko said the deal calls for the release of all people held captive by both sides within three weeks and he said an agreement was also made for Ukrainian Air Force pilot Nadia Savchenko to be released from a Russian jail, where she has been held for more than six months.
French President Francois Hollande, who along with German Chancellor Angela Merkel had negotiated with Poroshenko and Putin, thanked the Russian leader for "pressuring" the rebel leaders.
Fighting in eastern Ukraine has killed more than 5,350 people and forced hundreds of thousands of people to flee their homes since April.