Laying out clear conditions, president Barack Obama and Western allies opened a pathway for Russia to ease tensions in Ukraine but pointedly warned Moscow it could face new sanctions within weeks if Vladimir Putin fails to go along.
The leaders, who were gathered in Brussels for a wealthy-nations summit, said the Russian president could avoid tougher penalties in part by recognizing the legitimacy of the new Ukrainian government and ending support for an insurgency in eastern cities that is widely believed to be backed by the Kremlin.
There was no mention of rolling back Russia's annexation of the Ukrainian region of Crimea, which precipitated the European crisis.
"We are at a point where Mr Putin has the chance to get back into a lane of international law," Obama said on Thursday during a news conference with British prime minister David Cameron. But Obama also said the West "can't simply allow drift" in Ukraine, where insurgents continue to clash with government forces in eastern cities.
From Brussels, Obama and other leaders jetted to France ahead of events marking Friday's 70th anniversary of the D-Day Normandy invasion that paved the way for the Allied victory in World War II.
This time Putin was on the scene. And Cameron, French President Francois Hollande and German Chancellor Angela Merkel each were using the commemorations as a backdrop for separate meetings with the Russian president, who arrived in Paris.
Hollande in particular appeared to be embracing the diplomatic mantle, hosting Putin at Elysee Palace on Thursday night just after finishing dinner with Obama at a Paris restaurant.
The willingness of Western leaders to meet face-to-face with Putin for the first time since he annexed the Crimean Peninsula from Ukraine marked a noticeable shift in tactics.
While leaders have spoken with Putin by phone during the crisis, they had avoided meeting him in person and boycotted the summit he was to host in Russia this week, choosing instead to meet without him in Brussels.
It was the group's first similar summit in two decades without the participation of Russia.
Obama was not scheduled to hold a formal meeting with Putin, though the two men were expected to have some contact at a leaders lunch on Friday in Normandy.
Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov, who have met frequently during the crisis, huddled in the French capital on Thursday evening.