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Russian President Vladimir Putin discussed the possibility of a cease-fire during an informal talk with Ukraine's President-elect Petro Poroshenko on the sidelines of D-Day commemorations in France Friday.

It's the first encounter between the two leaders since Poroshenko was elected to head Ukraine last month.

French President Francois Hollande's office says the eagerly anticipated meeting between the Russian and Ukrainian leaders lasted 15 minutes, touching on key issues between the nations.

Putin and Poroshenko discussed how Russia could recognize the Ukrainian elections, and a possible cease-fire, according to an unidentified official at Hollande's office who was not authorized to speak publicly.

The Kremlin said Putin and Petro Poroshenko, called for the "soonest end to bloodshed in southeastern Ukraine and combat by both parties, the Ukrainian armed forces and supporters of the federalization of Ukraine," in a statement carried by Russian news wires.

The brief interaction took place after world leaders gathering for the commemoration posed for a group photo. After the photo, most of the leaders walked into a nearby building for lunch. But Putin, Poroshenko and German Chancellor Angela Merkel stayed outside the door, chatting together.

Reporters observing the exchange couldn't hear any of the conversation. It wasn't clear whether the conversation continued inside, or there were two meetings. A Reuters reporter at the scene did not see a handshake between the two men. French diplomats said before the event they would see a handshake as tacit acknowledgement by Putin that he recognizes Poroshenko's legitimacy the day before he is sworn in, opening the door for dialog.

Friday’s discussion comes during a week of intense diplomacy aimed at resolving the crisis in Ukraine.

Meanwhile, deadly violence in the eastern part of the country has persisted. At least 15 pro-Russian rebels were killed Thursday in clashes with government troops at a border crossing with Russia, an aide to the Ukrainian interior minister said.

In recent weeks, Ukrainian officials say more than 200 people have died -- a figure which can't be independently confirmed -- in fighting between Ukrainian government troops and pro-Russian rebels.

Candy magnate Poroshenko, who is to be sworn in Saturday as Ukraine's next president, has promised a comprehensive plan to put an end to the hostilities in the east as soon as he assumes office.

Putin held his first face-to-face meetings with Western leaders in France this week since pro-European protesters pushed out Ukraine's Russia-friendly president in February, Russia annexed the Crimean Peninsula, and the U.S. and EU imposed sanctions in response.

Some Western leaders appear ready to allow Putin back into the international fold after months of isolation. He met British Prime Minister David Cameron and French President Francois Hollande Thursday night, and Merkel on Friday morning in the Normandy town of Deauville.

Russian officials did not elaborate on the outcome of the talks between Putin and Merkel but the Russian presidential aide Yuri Ushakov said "the conversation mostly focused on the search for solutions and compromises," rather than dwelling on the differences, according  to the RIA Novosti news agency.

German government spokesman Christiane Wirtz said that the German chancellor "took the opportunity to remind Russia again of its great responsibility" and said that following the presidential election in Ukraine, the priority needs to be a "stabilization of the situation, in particular in eastern Ukraine

President Barack Obama and Western allies opened a pathway for Russia to ease tensions in Ukraine on Thursday but pointedly warned Moscow it could face new sanctions within weeks if Putin fails to go along. The leaders 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.

Speaking on a television show, Ukrainian interior ministry aide Anton Herashchenko said armed men came from Russia in trucks and an infantry vehicle and tried to cross the border at the village of Marynivka in eastern Ukraine Thursday. Those forces were supported by 100 rebels from the Ukrainian side.

Following the clash, Ukraine's government ordered the closing of parts of the border with Russia, including the Marynivka crossing, in an attempt to prevent armed men from infiltrating into its territory. The Russian Foreign Ministry said it was "outraged" by this move.

The Associated Press contributed to this report.