Fighting is reported to have subsided in eastern Ukraine after the government agreed a ceasefire with pro-Russian rebels.
Ukrainian President Petro Poroshenko confirmed on his Twitter account that a peace plan had been signed, while pro-Russian rebels also announced the news on the social media site.
There were initial reports of shelling in the rebel stronghold of Donetsk moments after the deal came into force at 4pm UK time, but the area later fell quiet.
The deal was reached after talks between Ukraine and pro-Russian rebels in the Belarussian capital, Minsk. Officials from Russia and the OSCE security watchdog also participated.
The deal saw an agreement on the release of prisoners on both sides, the delivery of humanitarian aid and the withdrawal of heavy weapons.
Speaking at a Nato summit in Wales, Mr Poroshenko said Kiev was also ready to grant a significant decentralisation of power and economic freedom to the turbulent east.
It is hoped the deal will go some way towards ending the five-month conflict that, according to the UN, has killed more than 2,600 people.
“Human life is the highest value and we must do everything possible and impossible to end the bloodshed and the suffering,” Mr Poroshenko said.
A spokesman for Russian President Vladimir Putin, meanwhile, said Russia was hopeful the ceasefire would be “thoroughly implemented” and that all sides would continue talks to reach a “full settlement of the Ukraine crisis.”
The West has accused Russia of sending troops and tanks to participate in the conflict, something Moscow has consistently denied.
. Despite the deal European leaders agreed to hit Russia with a fresh round of sanctions, including credit restrictions on Russian companies and export bans.Further Russian officials were issued travel bans and asset freezes.
Speaking after the summit, Prime Minister David Cameron indicated the sanctions might be lifted if the ceasefire leads to a more durable peace deal.
However US President Barack Obama admitted there was a degree of pessimism about the chances of lasting peace.
He said he was “hopeful, but based on past experience also sceptical that the separatists will follow through and the Russians will stop violating Ukraine’s sovereignty and territorial integrity”.
