Russian President Vladimir Putin held brief one-on-one talks on Friday with his US counterpart Barack Obama and Ukraine's Petro Poroshenko, in a possible diplomatic breakthrough that played out amid continuing violence in eastern Ukraine.
In remarks to reporters, Putin said the meetings with Poroshenko and other Western leaders were positive, and described talks with Obama as "substantial".
"I think the exchange of views was very positive," he said after attending the ceremonies marking the 70th anniversary of D-Day alongside US, British, French and German leaders.
Putin, however, said that Poroshenko, who will take his oath as president of Ukraine on Saturday, must first stop "punitive" operations in the eastern part of his country.
"Ukraine must demonstrate its good will. The repressive operation must be stopped."
It was the first meeting between the two men since pro-Western chocolate tycoon Poroshenko won Ukraine's presidential election on May 25.
Poroshenko welcomed the start of a dialogue with Putin and said it has "a good chance" of succeeding.
"The dialogue has begun, and that's a good thing," he said on Ukrainian television.
"A Russian representative will travel to Ukraine, and we will discuss with him the first steps towards a plan [to resolve] the situation... We have a good chance of implementing it."
The talks will take place on Sunday, he said.
Meanwhile, US Deputy National Security Advisor Ben Rhodes told AFP that during their separate meeting, Obama told Putin he must de-escalate tensions in Ukraine, or face deeper international isolation.
Russia's annexation of Crimea in March and the continuing standoff between pro-Russian fighters and the Ukrainian army the country's east have plunged Moscow's relations with the US and the European Union to a post-Cold War low.