The Pentagon and South Korea said Wednesday they will decide within a month whether to cancel next year’s major joint military exercises on the peninsula amid nuclear negotiations with the North.

The announcement came during a meeting between Defense Secretary Jim Mattis and his counterpart, South Korean Defense Minister Jeong Kyeong-doo, and could affect an annual spring field training exercise between the two countries called Foal Eagle.

President Trump canceled a major exercise and called them too expensive over the summer following his summit with North Korean dictator Kim Jong Un in June.

Jeong said the U.S. and South Korean military will conduct a review in November of upcoming exercises. “They will make the final decision on any major exercises in the next year before the first of December,” he said, according to a press pool report.

The last major exercise between the two countries was in April, and some analysts have said putting off the joint training for too long could start to erode their readiness for war, unless other types of smaller-scale training are emphasized.

Mattis denied the cancellations have had much of an effect so far.

“We are not right now concerned with a loss of combat capability. Clearly, as we go forward, we'll have to make adaptations to ensure we don't lose that capability,” Mattis said. “This is not a total suspension of all collaboration and military exercises. Certainly, large ones were put on hold, suspended temporarily in order to give the diplomats the best possible effort because we were making a good-faith effort on the military side.”

North Korea has tested nuclear bombs and intercontinental ballistic missiles that could reach U.S. cities, and the Trump administration has been attempting to negotiate with Pyongyang over the arsenal for months.