As denuclearization negotiations with North Korea appear to be faltering, Defense Secretary Jim Mattis seemed to be delivering a blunt and unequivocal message Tuesday: The U.S. could soon resume major military exercises with its South Korea allies.

“As you know we took the step to suspend several of the largest exercises as a good faith measure coming out of the Singapore summit. We have no plans at this time to suspend any more exercises,” Mattis said at a rare news conference in the Pentagon briefing room.

But then Mattis began to backtrack, insisting exercises could not be turned back on because they were never turned off, and that no decision would be made on next year’s exercises until next year, and then only after consultation with the State Department.

“We will work very closely with the secretary of state, and what he needs done we will certainly do to reinforce his effort, but at this time there has been no discussion of further suspensions,” Mattis said.

Even though Mattis made a point of saying the major exercises suspended two months ago were a “good faith” gesture, he would not say that North Korea was acting in bad faith, despite Pyongyang having taken no concrete steps to dismantle its nuclear weapons and missile programs.

Mattis seemed to be saying that despite making a show of canceling a couple of big war games, the U.S. was quietly continuing most of its exercises under the radar, so as not to undercut the diplomatic effort to persuade Kim Jong Un to live up to his commitment to denuclearize.

“We suspended several of the largest exercises, but we did not suspend the rest, so there are ongoing exercises all the time on the peninsula,” he said. “The reason you've not heard much about them is [so] North Korea could not in any way misinterpret those as somehow breaking faith with the negotiation. What it means in practical terms is that we're making no changes to the exercise program at this time.”

President Trump in June reportedly surprised other members of the administration when he announced the Pentagon would not conduct "war games" with South Korea following his meeting with Kim Jong Un in Singapore. At the time, Trump said the exercise cost a "fortune." The Pentagon followed through by halting planning of Ulchi Freedom Guardian.

"We save a fortune by not doing war games, as long as we are negotiating in good faith - which both sides are!" Trump tweeted in June.

On Friday, Trump tweeted that he had canceled Secretary of State Mike Pompeo's planned visit to Pyongyang this week because “I feel we are not making sufficient progress with respect to the denuclearization of the Korean Peninsula.”

Asked about whether President Trump’s tweeted boast that “There is no longer a nuclear threat from North Korea,” was still operative, Mattis said that amounted to asking for “a straightforward answer on a complex subject.”

“The bottom line is, there was progress made. The whole world saw that progress when the two leaders sat down. We also knew very clearly this was going to be a long and challenging effort to negotiate this away," he said.

Mattis, pressed on whether there was any hard evidence that North Korea had taken steps to denuclearize, deferred to the State Department.

“We stay in a supporting role,” he said.