Laura Smith-Spark-- CNN
(CNN)Marathon peace talks aimed at ending the bloody crisis in eastern Ukraine concluded Thursday in a breakthrough: A ceasefire that's due to start Sunday and an agreement for both sides to pull back heavy weapons.
If the ceasefire holds -- which is far from certain -- it could end a 10-month conflict that has claimed more than 5,000 lives, many of them civilians, and plunged East-West relations to their lowest point since the end of the Cold War.
The White House issued a statement with a tone of guarded optimism. "The United States welcomes the agreement reached today in Minsk..." it said. "The agreement represents a potentially significant step toward a peaceful resolution of the conflict and the restoration of Ukraine's sovereignty..."
The statement urged that all parties take "immediate, concrete steps" to fulfill their commitments. "Heavy weapons must be withdrawn from the conflict zone, and Russia must end its support for the separatists and withdraw its soldiers and military equipment from eastern Ukraine," the statement said.
Addressing reporters after the four-way overnight talks in Minsk, Belarus, Russian President Vladimir Putin said all parties had agreed to the ceasefire starting February 15 and called for restraint in the interim.
"I call on both sides to end the bloodshed as soon as possible" and come to a real political solution to the conflict, he said.
Putin said that both sides have agreed to pull back heavy weapons. The talks between Russia, Ukraine, France and Germany took so long, he said, because authorities in Kiev still refuse to have direct contact with separatists.
The agreement may not be perfect, she said, but it has provided a chance to improve matters in eastern Ukraine and is "clearly preferable to the situation if we had done nothing."
Merkel said Putin would be talking to separatist leaders about the deal. They were expected to travel to Moscow on Thursday to meet with Russian lawmakers.
Meanwhile, Ukrainian President Petro Poroshenko was heading to Brussels, Belgium, to brief European leaders on the situation. Both Hollande and Merkel paid tribute to his efforts on behalf of Ukraine in the talks.
European Council President Donald Tusk said that the agreement was "welcome news and gives hope" but that hope was not enough. "The real test is the respect of the ceasefire on the ground," he said.
He added that after speaking with Merkel, his feeling was "that we should remain extremely cautious."