US national security advisor John Bolton denied Sunday that last week’s nuclear summit with North Korea was a failure, despite President Donald Trump coming home empty-handed. A high-stakes second meeting to strike a disarmament deal with the North’s Kim Jong Un broke up in disarray Thursday in Hanoi, without even a joint statement.

Bolton told CBS’s “Face the Nation” that Trump’s failure to obtain commitments from Pyongyang on destroying its nuclear capability should be seen as “a success, defined as the president protecting and advancing American national interests.” He said the issue was whether North Korea would accept what the president called “the big deal” denuclearizing completely or something less, “which was unacceptable to us.”

“So the president held firm to his view. He deepened his relationship with Kim Jong Un. I don’t view it as a failure at all when American national interests are protected,” Bolton added.

The summit’s collapse followed the leaders’ historic meeting in Singapore that produced only a vague commitment from Kim to work “toward complete denuclearization of the Korean peninsula.” According to senior US officials, in the week leading up to the Hanoi summit, the North Koreans had demanded the lifting of effectively all UN Security Council economic sanctions imposed on Pyongyang since March 2016.

In return, Pyongyang was offering only to close part of the Yongbyon complex, a sprawling site covering multiple facilities and the North is believed to have other uranium enrichment plants.

“Sometimes you have to walk and this was just one of those times,” an unusually downbeat Trump said on Thursday, adding that he would “rather do it right than do it fast.” The president added Friday that his relations with Kim were “very good,” and a senior US official said the process was continuing, with “still ample opportunity to talk.”

Bolton’s evocation of progress was dismissed by leading Democrats, however, including House Intelligence Committee chairperson Adam Schiff, who described the Hanoi meeting as a “spectacular failure.”

“The president did give up a great deal, by going to that summit, by enhancing Kim Jong Un’s prestige on the world stage, by giving up those military exercises in the last summit and getting nothing for it,” Schiff told CBS. “This is, I think, the result of a president who is not prepared for these kinds of negotiations, a staff that is not well-prepared and is essentially flying by the seat of its pants.”

Much of the criticism of the summit was sparked by Trump’s remarks on the case of an American student tortured and left in a coma in North Korea. The president said he believed Kim’s claim that he didn’t know what happened to 22-year-old Otto Warmbier, who died days after being sent back to the United States in 2017. Bolton said Trump had been clear that Warmbier’s death was “barbaric and unacceptable,” although Schiff countered that the president’s “obsequious comments” had compounded the summit’s failure.

Bolton was touring the Sunday political shows the morning after the US and South Korea announced an end to key annual large-scale military exercises. The manoeuvres have been a perennial target of North Korean fury, condemned by Pyongyang as provocative rehearsals for war.

Since the Singapore summit, the US and Seoul have scaled back or scrapped several joint exercises, and US bombers no longer fly over South Korea. Opponents of scrapping the drills warn that it could affect the combat readiness of the combined US and South Korean forces and hand the North a strategic advantage on the divided peninsula.

Bolton sought to play down Saturday’s announcement; however, saying the policy remained unchanged since Singapore.