US President Donald Trump has issued an executive order authorising sanctions against individuals involved in an International Criminal Court investigation into whether US forces committed war crimes in Afghanistan.

A senior Trump administration official, without providing details, said the ICC investigation was “being pushed forward by an organisation of dubious integrity” and accused Russia of having a role.

The order authorises Secretary of State Mike Pompeo, in consultation with Treasury Secretary Steven Mnuchin, to block assets in the United States of ICC employees involved in the probe, the official said.

It also authorises Mr Pompeo to block entry into the US of these individuals.

Mr Trump has repeatedly assailed The Hague-based ICC set up to prosecute war crimes, genocide and crimes against humanity.

It has jurisdiction only if a member state is unable or unwilling to prosecute atrocities itself.

Afghanistan is a member of the ICC, though authorities in Kabul have argued that any war crimes should be prosecuted locally.

The US government has never been a member of the court, which was established in 2002.

The Trump administration imposed travel restrictions and other sanctions against ICC employees a year ago.

The ICC decided to investigate after prosecutors’ preliminary examination in 2017 found reasonable grounds to believe war crimes were committed in Afghanistan and that the ICC has jurisdiction.

The senior administration official, describing the order over a conference call, said the directive authorises sanctioned against any individual directly engaged in any effort by the ICC to investigate US personnel without US consent.

The official said the probe threatened to infringe on US sovereignty and that while the ICC was established to provide accountability, “in practice the court is an unaccountable, ineffective and out-of-control international bureaucracy that threatens American service members and intelligence officers and those of our allies”.

ICC prosecutor Fatou Bensouda wants to investigate possible crimes committed between 2003 and 2014, including alleged mass killings of civilians by the Taliban, as well as the alleged torture of prisoners by Afghan authorities and, to a lesser extent, by US forces and the CIA.

“We have reason to believe there is corruption and misconduct at the highest levels of the ICC’s office of prosecutor, calling into question the integrity of this investigation into American personnel,” the US official said.

“We are concerned that Russia may be manipulating the ICC by encouraging these allegations into US personnel.”

-AAP