The European Commission's new President Jean-Claude Juncker rings the bell as he chairs the first official meeting of the EU's executive body at the EU Commission headquarters in Brussels November 5, 2014.  [Photo/Agencies]

BRUSSELS - The new head of the European Commission said on Wednesday that British Prime Minister David Cameron "has a problem" with other European leaders, risking further tainting relations with Cameron, who had sought to block his appointment.

Asked about criticism of the European Union's executive body by Cameron and Italian Prime Minister Matteo Renzi, European Commission President Jean-Claude Juncker said he had "no particular problem" with Renzi and no problem with Cameron.

"Mr Cameron has a problem with the other prime ministers," Juncker told his first Brussels news conference since taking office on Nov 1.

The comment risks re-igniting bad feeling between Cameron and Juncker after the British prime minister failed in June to block Juncker's appointment to head the EU's executive body.

Cameron labelled Juncker a "career Brussels insider" who would make it harder to achieve the reforms Cameron believes are needed to keep Britain in the EU, but he lost 26-2 when Juncker's appointment was put to a vote of EU leaders.

Cameron clashed with the European Commission last month after he was presented with a 2.1-billion-euro ($2.6 billion) EU budget bill, calling it "completely unacceptable".

He was backed by Renzi, who said at the same Brussels summit that there were times when even founding fathers of the EU would turn into Eurosceptics, faced with the EU's bureaucracy.

Juncker, referring to Cameron and Renzi, told the European Parliament on Tuesday he did not like the way several prime ministers were behaving after the summit and denied being the leader of a "gang of bureaucrats".

Expanding his criticism on Wednesday, Juncker denied that the relationship between EU governments and the Commission was not working, but said he would defend the Commission against unjustified criticism.

"To say that the Commission shouldn't interfere in areas which are part of economic coordination in Europe, to say that you are not going to accept lessons from bureaucrats, that is a way of describing the Commission which I am not happy with."

"Attempts to dismantle the Commission before it has even started work is something I will respond to," he said.

Juncker also said that current EU sanctions on Russia over its role in the Ukraine crisis would remain in place.

"My impression is that the sanctions we have will remain where and as they are," he said, adding that he intended to visit Ukraine at some point.