US National Security Adviser John Bolton insisted Sunday that last week’s nuclear summit with North Korea, which abruptly ended with President Donald Trump walking away without reaching an agreement, was not a failure.

The second meeting aimed at reaching an agreement on disarmament with the North’s Kim Jong Un ended in such disarray in Hanoi Thursday that the two did not even make a joint statement.

Bolton told the American television program Face the Nation that Trump’s failure to secure commitments from Pyongyang on eliminating 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” – total denuclearization – or something less, “which was unacceptable to us.”

Bolton added, “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.”

The summit’s collapse followed the leaders’ historic meeting in Singapore, which produced only a vague commitment from Kim to work “toward complete denuclearization of the Korean Peninsula.”

According to senior American officials, during 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.

However, North Korean Foreign Minister Ri Yong Ho disputed the US account, saying Pyongyang offered to dismantle all “nuclear production facilities in the Yongbyon area” in exchange for partial sanctions relief.

“Sometimes you have to walk and this was just one of those times,” Trump said on Thursday, adding that he would “rather do it right than do it fast.”

– with reporting by Agence France-Presse