"The sanctions have had impacts on third countries, and they violate international law," she told Japanese media outlets online Friday.
"The ICC system, based on the rule of law, which the international community has developed over the years, could collapse" if the sanctions continue, she added.
The ICC had launched an official investigation into alleged war crimes by US service members in Afghanistan. The court also issued arrest warrants, including for Israeli Prime Minister Benjamin Netanyahu.
These actions angered the United States, which is not an ICC member.
On June 5, the State Department announced economic sanctions against four judges involved in the investigation and issuing the warrants, based on an executive order enabling US sanctions against ICC personnel signed by Trump in February.
"ICC, which punishes individuals who lead wars, is the last bastion of international law," Akane said from The Hague, Netherlands. She also stressed the importance of maintaining the court's presence.
Akane called on ICC member states, including Japan, to take a stand against the US actions, urging Washington to change its decision.
[Copyright The Jiji Press, Ltd.]