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The United States will repeal or deny visas to International Criminal Court staff seeking to investigate Americans in Afghanistan or elsewhere and may take similar action to protect Israelis or other allied forces from prosecution, Secretary of State Mike Pompeo said Friday.

"We are determined to protect the American and allied military and civilian personnel from living in fear of unjust prosecution for actions taken to defend our great nation," Pompeo said.

The unprecedented move came amid a pending request by the ICC prosecutor's office to open a probe into possible war crimes by Afghan or U.S. personnel in Afghanistan and after national security adviser John Bolton, a vehement critic of the court, threatened punitive action in September.

The visa restrictions are "a part of the continued effort to convince the ICC to change course with its potential investigation and potential prosecution of Americans for their activities and our allies activities in Afghanistan," Pompeo told a press conference.

The secretary of state said the administration has already begun to carry out the visa restrictions but did not offer any more details.

Referring to court employees, Pompeo said that "you should know if you're responsible for the proposed ICC investigation of U.S. personnel in connection with the situation in Afghanistan you should not assume that you will still have or will get a visa or that you will be permitted to enter the United States."

Pompeo added that the administration was prepared to impose visa restrictions in other cases involving allies, including Israel. "These visa restrictions may also be used to deter ICC efforts to pursue allied personnel including Israelis without allies consent," he said.

The prosecutor for the ICC has a request pending to investigate possible war crimes in Afghanistan linked to Afghan and U.S. military and intelligence personnel, including at detention sites. A U.S. Senate Intelligence Committee report in 2014 concluded that interrogations of detainees after the 9/11 attacks in Afghanistan and elsewhere were "brutal and far worse than the CIA represented to policymakers and others."

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Pompeo also said the U.S. was ready to increase the pressure on the ICC if necessary.

"These visa restrictions will not be the end of our efforts. We are prepared to take additional steps including economic sanctions if the ICC does not change its course," he said, without elaborating.

The International Criminal Court in The Hague said it was aware of the U.S. announcement.

"The ICC, as a court of law, will continue to do its independent work, undeterred, in accordance with its mandate and the overarching principle of the rule of law," ICC spokesman Fadi El Abdallah said in an email.

He added that the ICC is a court of last resort that exercises its jurisdiction only when governments do not meet their responsibility to investigate and prosecute atrocities.

Human rights groups denounced the Trump administration's decision.

The move represents "a thuggish attempt to penalize investigators at the International Criminal Court for doing their job — investigating war crimes," said Andrea Prasow, deputy Washington director at Human Rights Watch.

"The Trump administration is trying an end run around accountability. Taking action against those who work for the ICC sends a clear message to torturers and murderers alike: Their crimes may continue unchecked," she said.

In September, after Bolton vowed to penalize the ICC if it did not abandon possible plans to investigate U.S. forces, the court said it would not be deterred by Washington's threat and would carry on its work.

The U.S. for decades promoted the idea of international criminal justice and was instrumental in establishing the Nuremberg trials after World War II, as well as more recent tribunals prosecuting war crimes in former Yugoslavia, Rwanda, Cambodia and elsewhere.

But Washington has never been a member of the ICC. In 2000, the Clinton administration signed the Rome statute that set up the court but never submitted it to the Senate for ratification as there was strong bipartisan opposition to allowing American troops to be prosecuted outside of the U.S.

Under George W. Bush's administration, Bolton, as a senior State Department official, led the effort to withdraw the United States from the statute for the ICC.

The Obama administration had a less hostile stance toward the court and lent some limited support to the ICC's investigations, according to legal experts.

The ICC is the only permanent international criminal tribunal with a mandate to investigate and prosecute the crimes of genocide, crimes against humanity, war crimes and aggression.

There are currently 123 countries that have ratified the Rome Statute and are members of the ICC.