Listen Live

(CNN) — The US and South Korea are expected to announce that a critical joint military exercise has been scaled back because the coronavirus outbreak is severely limiting the ability of both nation’s militaries to participate, according to three US officials.

This would be the first major impact of coronavirus on US military readiness, according to the officials. Without the full exercise, the US could lose ground in being able to quickly conduct future operations in a coordinated and highly synchronized manner with South Korea against the north in a crisis one of the officials said.

The two sides are discussing the final details of the reduced effort. The command overseeing US forces in Korea, along with the South Korean military, could make an announcement as soon as late Tuesday night in the US, early Wednesday morning in South Korea, the officials said.

The first exercise involved is a so-called command post exercise scheduled to begin in the next several days. These types of exercises simulate the essential ability of top commanders and their senior staffs on both sides practicing precisely how they would operate together in a crisis. In South Korea, this is vital training as both sides would operate jointly in any combat crisis against North Korea.

It is not yet clear if any field exercises will be affected.

In a joint Pentagon press conference, Monday with the South Korean Minister of Defense, US Defense Secretary Mark Esper said the scaleback was being considered but insisted it would not have a military impact.

“I’m sure that we’ll remain fully ready to deal with any threats that we might face together,” Esper told reporters.

But US officials say that when exercises are scaled back or canceled as they were in August 2018, capabilities are particularly impacted because of the regularly scheduled high rate of changes in assignments for both nations forces. That can mean each year more than 50 percent of troops are replaced with newly assigned forces that may not have experience in commanding in Korea.