The US and Russian foreign ministers expressed cautious optimism after holding talks in Geneva today to end fighting in Ukraine, where the UN says more than 6,000 people have died in less than a year.
The meeting between John Kerry and Sergei Lavrov in Geneva was just one of several attempts at mediation on the conflict Monday, as high-stakes talks to resolve a bitter gas dispute between Kiev and Moscow were also due in Brussels.
Speaking separately after their 80-minute meeting, Kerry and Lavrov both cautiously said a February 15 ceasefire was on the right track, despite repeated breaches of the peace deal that have left hundreds dead.
The Russian foreign minister welcomed "tangible progress" in the implementation of the agreement reached in Minsk last month, saying "the ceasefire is being consolidated, heavy weapons are withdrawn."
Kerry, meanwhile, said he was "very hopeful" that his talks with Lavrov would help bring about the change needed to end fighting.
"Our hope is that within the next hours, and certainly not more than days, this (ceasefire) will be fully implemented," he said.
Underlining this momentum, the Russian, Ukrainian, French and German leaders agreed to hold four-way telephone talks on the crisis Monday evening, the Interfax news agency quoted a Kremlin advisor as saying.
But Kerry cautioned that there so far had been "a kind of cherry-picking, a piecemeal selectivity to the application of the Minsk agreements."
While fighting has broadly halted along much of Ukraine's frontline, several incidents took place over the weekend, with press photographer Sergiy Nikolayev killed by a mortar shell and eight soldiers injured by rebel fire.
Ukraine's army said today that one soldier had been killed, but added the ceasefire was still broadly holding.
Both sides have also begun to pull back some heavy weaponry from the frontline, but monitors from the Organization for Security and Cooperation in Europe have said it is too early to confirm a full pullback.
"I underscored this morning that if there continues to be this broad swathe of non-compliance... Then there would be inevitable consequences that would place further strain on Russia's economy," Kerry said, referring to further sanctions that the US and EU are working on.
The United Nations, meanwhile, cast a cloud on hopes raised by the talks with a report that painted a bleak picture of developments in the country.
"More than 6,000 lives have now been lost in less than a year due to the fighting in eastern Ukraine," UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein said in a statement.
