Updated

Complicating the West's efforts to isolate Russia, the Kremlin announced Thursday that Vladimir Putin will join President Barack Obama and European leaders in France next month for a ceremony marking the 70th anniversary of the D-Day invasion that hastened the end of World War II.

The June 6 commemoration would mark the first time Putin and Western leaders have come face-to-face since the outbreak of the crisis in Ukraine. The U.S. and Europe have condemned Russia's provocations, ordering sanctions on Putin's inner circle and cutting Russia's ties to some international organizations.

Still, leaders from Germany and France publicly welcomed Putin's decision to attend the observance at Normandy, raising questions about the effectiveness of recent efforts to ostracize the Russian president over Ukraine. And while the White House said Obama would not meet one-on-one with Putin, U.S. officials did not appear to be seeking to stop him from attending.

"We would not expect France to dis-invite Russia from this historic event commemorating World War II because of what's taking place in Ukraine," White House spokeswoman Caitlin Hayden said. "The events in Normandy on June 6 are focused on remembering the sacrifices of all our World War II veterans." Millions of Russian lives were lost in the war against Nazi Germany.

Yet Putin's presence is sure to intrude on, if not overshadow, the commemorations of the Normandy landings by allied forces. Even without a formal meeting between Putin and Western leaders, there will be heightened interest in their interactions, particularly between Obama and Putin, who have a history of tense public encounters.

"If this goes forward, this is not going to be about Normandy and the second world war," said Heather Conley, a Europe scholar at the Center for Strategic and International Studies. "We're just going to be watching the body language."

International gatherings like the D-Day anniversary are often occasions where world leaders find themselves in the presence of their foes. Obama shook hands with Venezuelan President Hugo Chavez at a regional summit in 2009. He also exchanged a handshake and brief pleasantries with Cuban leader Raul Castro last year while both attended a memorial service in South Africa for Nelson Mandela.

French officials began inviting world leaders to Normandy months ago, well before Russia annexed the Crimean Peninsula from Ukraine and positioned 40,000 troops on Ukraine's border with the former Soviet republic. The guest list also includes Britain's Queen Elizabeth II, the leaders of other European countries on both sides of World War II, and the heads of former African colonies whose soldiers took part in the war.

The U.S. and Europe were largely in agreement about allowing Putin to attend and felt it was appropriate to separate the war commemorations from the current geopolitical conflict, according to a Western diplomat, who spoke on the condition of anonymity because the diplomat was not authorized to discuss the Ukraine crisis publicly.

Putin spokesman Dmitry Peskov said details of the Russian leader's visit were still being worked out.  Most of the international leaders in attendance are expected to attend a lunch and formal ceremony on June 6, with other events scheduled throughout the week.

German Chancellor Angela Merkel welcomed the news of Putin's visit, saying she "had hoped that despite the different opinions and the great conflict we have right now, a joint remembrance of a difficult time -- of World War II -- is possible."

Merkel's comments were echoed by French President Francois Hollande. He told a French television station Thursday that while he has differences with Putin, he has not forgotten the millions of Russian lives that were lost in the war.

The victory over Nazi Germany remains a source of great pride in Russia.

Putin's decision to attend the D-Day commemoration could undermine what was supposed to be a strong show of U.S. and European unity against Russia that same week. Following Russia's annexation of Crimea, Western allies canceled plans to attend a Group of Eight Summit that Putin was scheduled to host in early June in Sochi, site of the 2014 Winter Olympics.

Instead, the seven other nations in the international economic forum will gather without Russia in Brussels before heading to Normandy.

Despite efforts to deepen Russia's isolation, U.S. and European officials acknowledge that it would be almost impossible to fully cut off ties with Russia. European nations have deep economic connections, particularly with Russia's robust energy sector. Russia is also closely involved with several of Obama's top foreign policy priorities, even negotiating alongside Washington in talks aimed at curbing Iran's nuclear program.