The United States designated Iran’s elite Revolutionary Guard Corps as a foreign terrorist organization, President Donald Trump said on Monday, marking the first time Washington has formally labeled another country’s military a terrorist group.

Trump said in a statement that the “unprecedented” move “recognizes the reality that Iran is not only a State Sponsor of Terrorism, but that the IRGC actively participates in, finances, and promotes terrorism as a tool of statecraft.”

“The IRGC is the Iranian government’s primary means of directing and implementing its global terrorist campaign,” Trump said in a statement.

The designation “makes crystal clear the risks of conducting business with, or providing support to, the IRGC,” Trump said.

“If you are doing business with the IRGC, you will be bankrolling terrorism.”

The US has in the past blacklisted dozens of entities and people for affiliations with the IRGC, but not the organization as a whole.

In 2007, the US Treasury designated the IRGC’s Quds Force, the unit in charge of operations abroad, “for its support of terrorism,” and has described it as Iran’s “primary arm for executing its policy of supporting terrorist and insurgent groups.”