The International Criminal Court (ICC) on Thursday hit back at a decision by U.S. President Donald Trump to authorize sanctions against any official investigating American troops over alleged war crimes in Afghanistan.

Trump said that the United States would block U.S. property and assets of anyone from The Hague-based tribunal involved in probing or prosecuting U.S. troops.

Under the new executive order, any individuals who "have directly engaged in any effort by the ICC to investigate, arrest, detain, or prosecute any United States personnel without the consent of the United States" or have attempted the same against a U.S. ally without that country's consent may be subject to sanctions.

In a White House statement released on Thursday, the ICC was criticized as an "unaccountable and ineffective international bureaucracy" that pursues "politically-motivated" investigations against the United States and its allies.

Trump administration has denied the authority of the ICC, with the U.S. not being a member of the group. Currently, the ICC has a total of 104 member countries.

"These attacks constitute an escalation and an unacceptable attempt to interfere with the rule of law and the Court's judicial proceedings," the ICC said in a statement.

After a long-running legal process, the court said in March that an investigation into the Afghan war could go ahead.

The Trump administration has been livid over the possibility of a probe into atrocities in Afghanistan, America's longest-running war.

But the ICC said the "unprecedented" sanctions "undermine our common endeavor to fight impunity and to ensure accountability for mass atrocities".

The court added: "An attack on the ICC also represents an attack against the interests of victims of atrocity crimes, for many of whom the Court represents the last hope for justice."