National Security Adviser John Bolton suggested Sunday that President Trump will not meet with Kim Jong Un unless the North Korean leader agrees to give up his country’s entire nuclear weapons program.

Bolton told “Fox News Sunday” that the leaders are still negotiating a time and place for such a meeting, but that finalizing such logistics hinge on Kim abandoning his nuclear program.

“If, in fact, Kim has made a strategic decision to give up his entire nuclear weapons program, then I think deciding on the place should be fairly easy,” Bolton said.

Bolton said world leaders -- including South Korean President Moon Jae-in -- have lauded Trump for bringing Kim to the negotiating table with painful economic sanctions and “political-military” pressure.

A meeting between Trump and Kim would mark the first time that the leaders of the United States and North Korea have met.

"It's taken a long time, many, many decades to get here," Trump said Friday. "Let's see what happens."

Bolton spoke to Fox News just two days after Moon and Kim held a historic summit on the North Korea-South Korea border, where they vowed to remove nuclear weapons from the Korean Peninsula, without identifying specific, new measures to achieve that goal.

The summit was almost inconceivable a few months ago, after a year when the bordering countries seemed on the verge of war.

The Koreas have technically remained at war since the 1950-1953 Korean War, which was only stopped via an armistice. The two countries have agreed to stop all hostile acts over "land, sea and air" that can cause military tensions and clashes.

World leaders hope Trump and Kim can perhaps further solidify or advance the Korean agreement if they indeed meet in May or June, as projected. However, they remain skeptical.

Trump tweeted Saturday that the logistics for his planned meeting with Kim Jong Un are “going very well.”

A meeting between Trump and Kim also seemed impossible until recent weeks, amid North Korea’s recent testing of a nuclear warhead and ballistic missiles that could launch a nuclear weapon. Just four months ago, Kim threatened the U.S. with nuclear weapons.

The tests resulted in the stiff economic sanctions and an alarming exchange of public name-calling between Trump and Kim that sparked fear of war. Trump had called Kim “Little Rocket Man.” And Kim had called Trump a “dotard.”

Bolton acknowledged Sunday that Trump is “eager to (meet) as soon as possible.”

However, he also made clear that nobody in the administration is “starry-eyed” about Kim indeed dismantling his nuclear weapons program and sticking to his promise.

Bolton also suggested that Kim would have to give up his “entire nuclear program” before sanctions are lifted.

The Associated Press contributed to this report.