The United States canceled a joint amphibious landing drill scheduled for next month with South Korea, Seoul’s Marine Corps said on Monday, after Washington cited constraints on the availability of U.S. forces due to the war in Iran.

The U.S. Marine Corps formally notified its South Korean counterpart in June that force availability would be constrained for the division-level exercise, known as Ssangyong, a South Korean Marine Corps spokesperson told a press briefing.

The allies remain in close consultations on resuming the drills, the spokesperson said. He did not specify what measures might be taken to prevent future cancelations or to make up for lost training opportunities.

U.S. Forces Korea did not immediately respond to a request for comment.

Later on Monday, the U.S. State Department said that Secretary of State Marco Rubio had spoken with South Korean Foreign Minister Cho Hyun about a “range of issues” in their alliance.

Rubio told his South Korean counterpart that Washington and Seoul need to remain in close coordination on matters integral to their alliance, according to a State Department statement.

The cancelation of the amphibious landing drill follows U.S. President Donald Trump’s surprise order to scale back a separate annual joint military exercise that ended last Friday, citing the cost and Seoul’s refusal to take part in the Iran war.

Trump also wrote on his Truth Social platform that the Ulchi Freedom Shield drills sent “a signal that was totally inappropriate and hostile, to a Country that, as long as Donald J. Trump has been President, has been unthreatening and respectful.” Despite the reduction of the exercises, Pyongyang fired 10 short-range ballistic missiles last week and issued a statement denouncing the exercises.

North Korea has long condemned such joint exercises as rehearsals for invasion.