PARIS, Sept. 11 (Xinhua) -- France on Tuesday affirmed its support to the International Criminal Court (ICC) after Washington menaced ICC if it would investigate into alleged war crimes committed by U.S. servicemen during the war in Afghanistan, foreign ministry's spokesperson said.

"France, with its European partners, supports the International Criminal Court, both in its budgetary contribution and in its cooperation with it," Foreign Ministry spokeswoman Agnes von der Muhll said.

"The court must be able to act and exercise its prerogatives without hindrance, independently and impartially, within the legal framework defined by the Rome Statute," she added.

The Hague-based tribunal, "is a major step in the fight against the impunity to which we and the United States, are very attached," she stressed during a press briefing.

On Monday, U.S. National Security Adviser John Bolton threatened to impose tough sanctions if the ICC would go ahead in investigation mainly by banning the court judges and prosecutors from entering the American soil and prosecute them in the United States.