The United States has imposed sanctions on senior officials of the International Criminal Court (ICC), including Chief Prosecutor Fatou Bensouda.
Secretary of State Mike Pompeo accused the court of “illegitimate attempts to bring Americans to its jurisdiction.”
The Hague-based ICC is currently investigating whether US forces have committed war crimes in Afghanistan.
The United States has criticized the court since its founding and is among a dozen states that have not signed up.
President Donald Trump issued an executive order in June that allows the United States to freeze the assets of ICC employees and prevent them from entering the country.
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Speaking to reporters on Wednesday, Pompeo said Ms Bensouda and Phakiso Mochochoko, head of the Competence, Complementarity and Cooperation Division, were to be punished under the order.
Rejecting the ICC as a “completely broken and corrupt institution”, he said those who continued to “materially support these people also risked exposure to sanctions”.
The US State Department has also restricted the issuance of visas for ICC personnel involved in “efforts to investigate US personnel.”
The ICC began investigating alleged war crimes committed by the United States and others in the Afghan conflict earlier this year.
At the time, Mr. Pompeo promised to protect Americans from the investigation, calling it “a truly breathtaking gesture by an irresponsible political institution posing as a legal body.”
A 2016 ICC report said there were reasonable grounds to believe that the US military had committed acts of torture in secret CIA-run places of detention.
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The actions of the Taliban, the Afghan government and US troops since May 2003 should be reviewed by the tribunal.
Afghanistan is a member of the court, but officials there have also expressed opposition to the investigation.