The US has revoked the visa of the international criminal court’s chief prosecutor in response to her intention to investigate potential war crimes by US soldiers in Afghanistan.

A statement from the office of Fatou Bensouda, a Gambian national, said she would continue to pursue her duties for the court, in The Hague, “without fear or favour” and that she would continue to travel to the US. She has not been restricted from visiting the UN headquarters in New York.

The US state department does not provide details of individual visa cases but made clear it was implementing the threat last month from the secretary of state, Mike Pompeo, to impose restrictions on any ICC staff who investigated US or allied personnel. The move marked a hardening of America’s policy of non-cooperation with the ICC, and a downgrading of the role of multilateralism.

“The United States will take the necessary steps to protect its sovereignty and to protect our people from unjust investigation and prosecution by the international criminal court,” a state department spokesperson said.

They added that visas would be denied to “ICC officials who are determined to be directly responsible for any ICC effort to conduct a formal investigation of US or allied personnel without the relevant country’s consent”.

The state department said the US would not “interfere with travel to the UN for official UN purposes”.

The US has refused to recognise the ICC since its inception in 2002, weakening the court’s authority and providing an excuse for other countries, most notably in Africa, to also pull their support. In 2017, Burundi became the first nation to leave the ICC.

Pompeo’s move came as he delivered another snub to multilateralism by skipping a meeting of G7 foreign ministers in France on Friday and sending his deputy, John Sullivan.

Bensouda’s office said she had an “independent and impartial mandate” under the Rome statute governing the ICC. “The prosecutor and her office will continue to undertake that statutory duty with utmost commitment and professionalism, without fear or favour,” it added.

Bensouda makes regular trips to the UN in New York, where she gives briefings to the security council. The UN office is seen as covered by a form of diplomatic immunity.

“It is our understanding that [the visa withdrawal] should not have an impact on the prosecutor’s travel to the US to meet her obligations to the UN,” a spokesperson for her office said.

Bensouda asked ICC judges in November 2017 for authorisation to open an investigation into alleged war crimes in Afghanistan by the Taliban, Afghan government forces and international forces, including US troops.

The investigation is also expected to examine CIA activity in detention centres in Afghanistan. The court has not yet decided whether to launch a full-blown investigation that would cover events after 2002.

Pompeo said on 15 March that the ICC was “attacking America’s rule of law”, as he announced a policy of imposing visa restrictions on “individuals directly responsible for any ICC investigation of US personnel”.

“If you’re responsible for the proposed ICC investigation of US personnel in connection with the situation in Afghanistan you should not assume that you still have, or will get, a visa or that you will permitted to enter the United States,” Pompeo said.

Last September, the US national security adviser, John Bolton, launched a blistering attack on the ICC in a speech to the conservative Federalist Society in Washington, denouncing the court as invalid and “antithetical to our nation’s ideals”.

“We will provide no assistance to the ICC,” Bolton said. “We will let the ICC die on its own. After all, for all intents and purposes, the ICC is already dead to us.”

Bolton threatened the ICC with sanctions and possible prosecution of its officials if it proceeded with investigations into alleged war crimes committed by US military and intelligence staff during the war in Afghanistan or investigated Israel or other US allies.

In response, the UN-backed court said it would not be intimidated or dissuaded from its global mission.

“The ICC, as a court of law, will continue to do its work undeterred, in accordance with those principles and the overarching idea of the rule of law,” it said.