Paris - While US President Barack Obama is very intelligent and charismatic, he is "not always at his best when it comes to decisions and efficiency", French President Nicolas Sarkozy was quoted Thursday as saying. His office quickly denied the remarks.

"He has only been elected for two months and has never managed a ministry in his life," Sarkozy was quoted as saying by Liberation newspaper.

And there were things on which Obama had no opinion, he was quoted as adding. However, Sarkozy's office at the Elysee Palace within hours denied all the remarks.

Liberation quoted as source unnamed people present on Wednesday at a meeting at the Elysee Palace at which the French president briefed a group of MPs on the results of the recent G20 summit.

Sarkozy was further quoted as saying that during the recent summit meetings in Europe he had told Obama, in reference to the European Union's climate agreement, that "I don't think you have quite understood what we (the EU) have done on the subject of CO2."

Sarkozy was further quoted as saying of German Chancellor Angela Merkel: "When it became clear to her what state her banks and her industry were in, she had no choice but to give in to my line."

He was apparently referring to Merkel's initial reluctance to agree to a comprehensive economic package.

Sarkozy was also quoted as dismissively remarking about Spanish Prime Minister Jose Luis Rodriguez Zapatero: "Perhaps he's not particularly intelligent."