Former Trump national security adviser John Bolton called on U.S. armed forces to resume military exercises with South Korea, and ascertain the state of American troops in the region, following Kim Jong Un's recent statement on testing nuclear weapons.

Kim's cryptic remarks about the United States receiving a "Christmas gift" from North Korea had already stirred speculation, about the rogue nation planning to test the viability of an intercontinental ballistic missile, which could have the potential to deliver a nuclear warhead.

He then stoked fears of conflict on Tuesday when he spoke to party leaders, claiming he is no longer obligated to comply with a previously self-imposed moratorium on testing nuclear weapons and intercontinental ballistic missiles.

Bolton voiced his concerns publicly on Twitter Wednesday and suggested resuming canceled military drills and holding congressional hearings.

TRUMP URGED TO 'LOWER THE BOOM' ON NORTH KOREA AND NEW THREATS

"How to respond to Kim Jong Un’s threatening New Year’s remarks? The U.S. should fully resume all canceled or down-sized military exercises in South Korea," he tweeted. "Hold Congressional hearings on whether US troops are truly ready to “fight tonight.”

Kim also warned of a “new strategic weapon" on Tuesday, and accused the U.S. of making "gangster-like demands."

“The world will witness a new strategic weapon to be possessed by the DPRK in the near future,” he said,

President Donald Trump told reporters at Mar-a-Lago in Florida on Tuesday that he has a good relationship with Kim and expects the North Korean leader to stand by his word.

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“He likes me, I like him. We get along. He’s representing his country, I’m representing my country. We have to do what we have to do," Trump said.

“But he did sign a contract," the president added. "He did sign an agreement talking about denuclearization. And that was signed. ... I think he’s a man of his word."

In June, Trump made history by becoming the first sitting U.S. president to set foot in North Korea when he met with Kim face-to-face.

Fox News' Robert Gearty contributed to this piece