Former national security adviser John Bolton is questioning whether the Trump administration "really means it" when the president and other officials promise to denuclearize North Korea.

Speaking with Axios in an interview published Sunday, Bolton accused President Trump of bluffing on the vow to rid the hermit nation of nuclear weapons, saying the White House "would be pursuing a different course" if the pledge were true.

"The idea that we are somehow exerting maximum pressure on North Korea is just unfortunately not true," he said, calling the Trump administration's assertion that the country cannot have nukes a "rhetorical policy."

If North Korea follows through on its promised "Christmas gift" for the United States, which some believe is a sign that the country could resume long-distance missile tests, Bolton believes the White House should do something "that would be very unusual."

According to him, administration officials should admit they were wrong and say, "We've tried. The policy's failed. We're going to go back now and make it clear that in a variety of steps, together with our allies, when we say it's unacceptable, we're going to demonstrate we will not accept it."

"We're now nearly three years into the administration with no visible progress toward getting North Korea to make the strategic decision to stop pursuing deliverable nuclear weapons," Bolton said. "Time is on the side of the proliferator. The more time there is, the more time there is to develop, test, and refine both the nuclear component and the ballistic missile component of the program."

Trump has been working toward denuclearizing the Korean peninsula and promoting peace between North and South Korea since he took office. Over the summer, he made history as the only president to have crossed the Demilitarized Zone into North Korea. Around the same time, he left a summit with leader Kim Jong Un and declared, "There is no longer a nuclear threat from North Korea."

However, evidence has arisen, indicating that Kim has actually expanded the country's nuclear arsenal since. Some have estimated that there are between 20-30 nuclear warheads in North Korea. The nation has also been frequently testing missiles over the past year, something Trump has said doesn't bother him. Bolton, however, criticized the president's indifference.

"When the president says, 'Well, I'm not worried about short-range missiles,' he's saying, 'I'm not worried about the potential risk to American troops deployed in the region or our treaty allies, South Korea and Japan,'" he said.

North Korea has set an end-of-year deadline to conduct nuclear negotiations with the U.S. The president is expected to remain at his Mar-a-Lago club for at least two weeks after arriving there over the weekend, so it is unclear when or where the negotiations would take place.