Secretary of State Marco Rubio announced new sanctions Tuesday against two senior International Criminal Court officials, escalating the Trump administration’s campaign against a tribunal it accuses of unlawfully targeting Americans and officials from allied nations.

The sanctions target ICC President Tomoko Akane and senior trial lawyer Abdoulaye Seye. Rubio said both participated in efforts to exercise the court’s authority over officials from countries that have not accepted its jurisdiction.

“These individuals have directly engaged in efforts by the ICC to investigate, arrest, detain, or prosecute officials whose government has not consented to ICC jurisdiction,” Rubio said.

The United States is not a party to the Rome Statute, the 2002 treaty that established the ICC to prosecute genocide, war crimes and crimes against humanity. The Trump administration argues the court has no legitimate authority over Americans without U.S. consent.

“The ICC has repeatedly attempted to assert authority over nationals of the United States and other countries that have not consented to its jurisdiction or ratified the Rome Statute,” Rubio said. “This sets a dangerous precedent for all nations.”

The latest action follows Rubio’s launch last month of a broader diplomatic effort targeting the ICC. The confrontation intensified after three ICC judges sued the Trump administration in federal court in New York in June, challenging sanctions imposed against them last year.

Rubio has sharply criticized the court as an unaccountable international institution that threatens U.S. sovereignty. In a Wall Street Journal opinion piece last month, he accused the ICC of being “backed and run by a powerful network of leftist nongovernment organizations, smug globalists, and hostile Third World governments united by their enmity toward the U.S.”

The administration has also clashed with the ICC over its treatment of Israel, another country that is not a party to the Rome Statute.

The Trump administration imposed sanctions on the court last year after the ICC pursued Israeli officials over the country’s war against Hamas. The court issued arrest warrants for Israeli Prime Minister Benjamin Netanyahu and other Israeli leaders.

The administration maintains that neither the United States nor its allies should be subjected to prosecutions by an international court whose jurisdiction they have not accepted.