WASHINGTON, DC — The United States must remain vigilant against the ongoing threat posed by North Korea’s nuclear activities despite Kim Jong-un’s pledge to take steps towards “complete denuclearization,” the nominee to serve as the American ambassador in South Korea told lawmakers during his confirmation hearing on Thursday.

Retired Admiral Harry Harris’s comments came hours after U.S. President Donald Trump declared that the North Korea nuclear threat “no longer” exists, courtesy of Wednesday’s summit with Kim, adding that the world can “sleep well” as a result.

Nevertheless, Harris told the Senate Foreign Relations Committee hosting his confirmation hearing, “I think we must continue to worry about the nuclear threat.”

The prospective top envoy’s remarks came in response to Senator Robert Menendez (D-NJ) asking him whether he agrees with President Trump’s declaration Wednesday that the historic summit has rendered the world safe by ridding the globe of North Korea’s nuclear threat.

Citing the joint statement signed by the two leaders, which asserts Kim’s allegedly “firm and unwavering commitment to complete denuclearization of the Korean Peninsula,” President Trump said that the world could “sleep well” after the summit.

“There is no longer a Nuclear Threat from North Korea,” Trump proclaimed via Twitter, adding that “everybody can now feel much safer than the day I took office.”

During the confirmation hearing, Harris acknowledged that the Trump administration’s efforts against North Korea averted a war.

“I’ve spoken in the past about the need to bring Kim to his senses and not his knees, and I think the president’s efforts in Singapore did just that,” Harris noted.

Although he highlighted the need to remain vigilant, the prospective ambassador stressed that the world is in a “dramatically” better place as a result of the Trump-Kim summit

Harris, the former commander of U.S. Pacific Command (PACOM) who has been very outspoken about the North Korea nuclear menace, expressed support for Trump’s decision to stop military drills with South Korea, suggesting it is a move of good faith to see how serious Kim is in keeping his side of the bargain.

The retired admiral — very likely to be confirmed given the respect he elicits from both Democrats and Republicans — told Menendez:

In my previous capacity, I spoke very strongly about the need to continue with military exercises most notably in 2017, but we were in a different place in 2017 you know.

North Korea was exploding nuclear weapons, they were launching ballistic missiles almost willy-nilly, and if [a] war wasn’t imminent, it was certainly possible maybe even likely. I think today following the president’s summit with Kim Jong-un in Singapore I think we’re in a dramatically different place. I think that the whole landscape has shifted and I believe that we should give exercises, major exercises a pause to see if Kim Jong-un, in fact, is serious about his part of the negotiations.

On Wednesday, U.S. State Secretary Mike Pompeo further explained that the military exercises between the U.S. and South Korea would be suspended only in the midst of “productive, good-faith negotiations.”

“At the point, it’s concluded that they’re not, the president’s commitment to not have those joint exercises take place will no longer be in effect,” Pompeo told reporters, vowing to resume military drills if the nuclear negotiations fail.

The joint Trump-Kim statement is elusive when it comes to details for a timetable and how the Trump administration will get Kim to take significant steps towards the complete, verifiable, irreversible denuclearization of the Korean Peninsula.

The Trump administration has yet to provide a specific timeline for denuclearization in the wake of the summit.

However, Pompeo and President Trump have called for “rapid” denuclearization in the past.

On Wednesday, Pompeo did note that the administration intends to achieve “major disarmament” during Trump’s first term, or in the next two and a half years.

Acknowledging that the extent of North Korea’s nuclear capabilities is unknown,” Joseph Yun from the U.S. Institute of Peace (USIP) told lawmakers on June 5 denuclearization can take “ten years.”

Trump conceded that this week’s summit was just the beginning of an “arduous process,” stressing that sanctions against the North Korean regime would remain in place.