"We just did some in Hawaii, (at) Joint Base Lewis-McChord and Washington state. Even (in) Alaska we worked some scenarios, and we invite the ROKs to that. Obviously, not as many can come," he added, referring to the acronym for South Korea's official name, the Republic of Korea.

Most recently, Seoul and Washington decided to suspend the Vigilant Ace air exercise which was originally scheduled for December as part of efforts to continue dialogue with Pyongyang and keep it on a denuclearization track.

US Secretary of Defense James Mattis has also mentioned that the springtime Foal Eagle exercise with the South will be "reduced in scope" and that it is being "reorganized a bit" to keep it at a level that will not harm diplomacy.

Earlier this year, the allies also called off a series of exercises such as the summertime Ulchi Freedom Guardian -- a decision that sparked concerns that their defense posture could weaken when the North had yet to take tangible steps toward nuclear disarmament.

During the interview, Brown stressed the importance of exercises.

"If you don't exercise, it's kind of like preparing a team to go to the Super Bowl and you never practice or you never play a game. That wouldn't be very good," he said. "You want to play against the best competition. You want to work together so you're a well-organized, well-knit, close-cut team, and that's what we need."

But he assured that the long-standing alliance between Seoul and Washington remains firm.

"I have never seen in my 30-plus years working with [South] Korea, with the ROK, I've never seen the alliance more rock solid because when you get these challenges, it causes you to get closer together. And so it's a rock solid alliance," he said.

Meanwhile, Gen. Charles Brown, head of the US Pacific Air Forces, told reporters Monday that US bombers are no longer conducting flights over South Korea as Seoul asked for the pause of such missions to support diplomatic efforts, according to AFP.

"As we're going through the diplomatic aspect, we don't want to actually do something that's going to derail the diplomatic negotiations," Brown was quoted by AFP as saying. "So that's part of the reason why we're not doing (flights) over Korea."

The US has routinely carried out flight missions over the region as part of training sessions or to show its military might against the North and other potential challengers. (Yonhap)