The United States has cancelled a joint amphibious landing drill scheduled for next month with South Korea, Seoul’s Marine Corps says, as Washington cites constraints on the availability of US forces due to the war on Iran.

The US 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, according to Reuters.

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 cancellations or to make up for lost training opportunities.

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