A photo of Barack Obama in a campaign video for French President Nicolas Sarkozy is upsetting the team of Sarkozy's rival, Socialist Francois Hollande.

Hollande's campaign chief Pierre Moscovici said Friday he was surprised the photo of Obama and Sarkozy aired in the video and called the U.S. Embassy to discuss the matter. Hollande leads Sarkozy in polls before Sunday's election.

Another campaign staffer said Hollande's aides are furious, fearing the image suggests that Obama — who is widely popular in France — is taking sides in the French presidential race.

U.S. Embassy spokesman Paul Patin said "the U.S. government does not support any candidate."

But the front page of Sarkozy's campaign website says the French president is "respected and supported" by "most of his counterparts" — and listed Obama, Britain's David Cameron and Germany's Angela Merkel.

"We knew Cameron officially supported him, we knew Merkel officially supported him, but we had questions about Obama and wanted clarification," the Hollande campaign official said on condition of anonymity because she wasn't authorized to talk to the media.

If Hollande wins the election Sunday, concerns about Obama's backing for Sarkozy could color Hollande's first meeting with Obama two weeks later. The two men have never met.

The French presidential inauguration will take place no later than May 16, and the French leader is expected to travel to the U.S. two days later for summits of the Group of Eight and NATO.

Sarkozy is arguably the most U.S.-friendly French president in a half-century, and worked to improve relations with Washington after his election in 2007.