The top U.S. envoy on North Korea says Washington is ready to restart nuclear negotiations with North Korea.

Stephen Biegun made the comments Wednesday, a day after the U.S. and South Korea ended their regular military exercises that North Korea calls an invasion rehearsal. During the training, North Korea raised tensions with its own missile and other weapons tests.

Biegun told reporters in Seoul that "we are prepared to engage as soon as we hear from our counterparts in North Korea."

U.S. special envoy for North Korea Stephen Biegun, left, talks with his South Korean counterpart Lee Do-hoon, second from right, during their meeting at the Foreign Ministry in Seoul, South Korea, Wednesday, Aug. 21, 2019. (Kim Hong-JiPool Photo via AP)

U.S. special envoy for North Korea Stephen Biegun, left, talks with his South Korean counterpart Lee Do-hoon, second from right, during their meeting at the Foreign Ministry in Seoul, South Korea, Wednesday, Aug. 21, 2019. (Kim Hong-JiPool Photo via AP)

Negotiations between Washington and Pyongyang collapsed after a second summit between President Donald Trump and North Korean leader Kim Jong Un in Vietnam in February ended without any agreement.

Trump and Kim met again at the Korean border in late June and agreed to resume negotiations.

U.S. special envoy for North Korea Stephen Biegun, left, talks with his South Korean counterpart Lee Do-hoon during their meeting at the Foreign Ministry in Seoul, South Korea, Wednesday, Aug. 21, 2019. (Kim Hong-JiPool Photo via AP)

U.S. special envoy for North Korea Stephen Biegun, left, talks with his South Korean counterpart Lee Do-hoon during their meeting at the Foreign Ministry in Seoul, South Korea, Wednesday, Aug. 21, 2019. (Kim Hong-JiPool Photo via AP)