The leaders of France, Germany, Russia and Ukraine are meeting in Paris to consolidate a fragile peace in Ukraine, as the conflict is overshadowed by President Vladimir Putin's dramatic intervention in Syria's war.
Fighting has all but stopped in eastern Ukraine and with peace closer than ever, leaders are seeking a lasting political solution to the 17-month conflict that has left more than 8000 dead.
The main points of contention are the holding of local elections in separatist eastern Ukraine, ensuring access for international observers to pro-Russian rebel zones, and the removal of heavy weapons from the front line.
"I am counting on the fact that the Minsk accords will be carried out, which unfortunately today is not the case," Putin said in Moscow on Thursday (local time), speaking about the peace deal struck in February.
"We are far from a resolution, but there are elements that boost our confidence that the crisis can be overcome and the most important point is that there is currently no shooting."
However, observers fear Moscow's engagement in Syria will draw attention from the peace process at this crucial time.
"It's obvious" that developments in Syria will "influence the climate" of the long-planned Ukraine talks, a member of Hollande's entourage said.
Ukraine officials have suggested that with his action in Syria, Putin is hoping to leverage a better deal on Ukraine, particularly an easing of painful economic sanctions that were imposed after Russia annexed the Crimean peninsula last year.
"This is an absolutely absurd interpretation of what is happening," Russian Foreign Minister Sergei Lavrov said on Thursday.
In Paris on Friday, Putin will start the day with bilateral talks with French leader Francois Hollande and German Chancellor Angela Merkel on Syria.
However, officials insist the main order of the day is ironing out kinks in the peace process in Ukraine, at an afternoon summit between the four leaders.
After repeated violations of previous truces, the latest ceasefire, called last month, has been largely observed by pro-Russian rebels and Ukrainian forces, raising hopes that the conflict is drawing to a close.
On Wednesday, Ukraine and the rebels agreed to withdraw smaller weapons from the buffer zone between their forces.
However, the warring sides have yet to find a lasting political solution to the crisis that plunged relations between Moscow and the West to their worst levels since the Cold War.
Despite Russian denials, Ukraine and the West accuse Moscow of covertly supporting the rebels with troops and weapons after an uprising installed a pro-EU government in Kiev last year.