WASHINGTON -- The United States will revoke or deny visas to any International Criminal Court (ICC) individuals investigating alleged war crimes by U.S. forces or allies, including in Afghanistan, Secretary of State Mike Pompeo says.

"I'm announcing a policy of U.S. visa restrictions on those individuals directly responsible for any ICC investigation of U.S. personnel," Pompeo told a news conference in Washington on March 15.

Pompeo said the policy has already been implemented, but he did not provide details of who has been affected, citing confidentiality rules.

"But 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 you will still have or will get a visa or that you will be permitted to enter the United States," Pompeo warned.

ICC prosecutors in November 2017 sought authorization from judges to initiate an investigation into alleged war crimes and crimes against humanity in Afghanistan since May 1, 2003.

The request covered countries where the U.S. Central Intelligence Agency held prisoners.

Judges are reviewing material submitted by prosecutors and must decide whether to authorize an investigation.

Pompeo said the visa restrictions “may also be used to deter ICC efforts to pursue allied personnel, including Israelis, without allies' consent."

He added that Washington was "prepared to take additional steps, including economic sanctions, if the ICC does not change its course."

The Hague-based ICC did not comment specifically about the visa threat, but it insisted it is an independent and impartial institution and would continue to do its work "undeterred" by any U.S. actions.

Human Rights Watch called the announcement a "thuggish attempt to penalize investigators" at the court and that it sends “a message to torturers and murderers alike: Their crimes may continue unchecked.”

Pompeo’s comments follow a threat by the administration of President Donald Trump last September to ban ICC judges and prosecutors from entering the United States and to place sanctions on funds they have in the country if the court were to launch an investigation into war crimes in Afghanistan.

The U.S. national security adviser, John Bolton, at the time warned that "if the court comes after us, Israel, or other U.S. allies, we will not sit quietly."

"We will ban its judges and prosecutors from entering the United States. We will sanction their funds in the U.S. financial system, and we will prosecute them in the U.S. criminal system," Bolton said.

Pompeo did not mention potential criminal prosecution of ICC members in his comments.

He said the United States declined in 1998 to join the court “because of its broad, unaccountable prosecutorial powers and the threat it poses to American national sovereignty.”

The ICC was established in 2002 to prosecute war crimes, genocide, or crimes against humanity when a country is unable or unwilling to prosecute perpetrators themselves.

The United States is among a dozen countries, including China and Russia, that have not ratified the Rome Treaty that created the ICC.

With reporting by Reuters, AP, and dpa