Former national security adviser John Bolton says Trump is not 'exerting maximum pressure' on North Korea

President Donald Trump's former national security adviser, John Bolton, criticized what he called the administration's "rhetorical policy" against North Korea's nuclear weapons.

Speaking to Axios late last week in an interview published Sunday, Bolton said he doesn't believe the Trump administration "really means it" when pledging to halt North Korean nuclear efforts that could threaten the United States. Otherwise, Bolton said, the administration "would be pursuing a different course."

His comments come as North Korea is mounting pressure on the U.S. to resume stalled nuclear talks and give in to certain demands by the end of the year. North Korea has called for Washington to drop its "hostile policy" before it will resume denuclearization talks.

Earlier this month, North Korea warned that if talks weren't resumed by the deadline with concessions for what experts interpret as demands for sanctions relief, the U.S. would not be happy about a "Christmas gift" delivered by leader Kim Jong Un.

"The idea that we are somehow exerting maximum pressure on North Korea is just unfortunately not true," Bolton told Axios.

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Since the summit in February between Kim and Trump collapsed, North Korea has been calling for new terms for a deal and has conducted missile tests. Bolton had urged Trump to take a more hard-line approach to the talks.

“We have offered any number of creative ways to proceed with feasible steps and flexibility in our negotiations to reach balanced agreements that meet the objectives of both sides,” Stephen Biegun, Trump's special representative for North Korea, said last week.

“We are fully aware of the strong potential for North Korea to conduct a major provocation in the days ahead," Biegun said. "To say the least, such an action will be most unhelpful in achieving lasting peace on the Korean Peninsula.”

Bolton said that Biegun's remarks were "a late entry but a clear winner in the 'Understatement of the Year Award' contest."

"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.

Bolton said that if North Korea follows through on its threats for action in the coming days, the administration should admit it had made a mistake 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."

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"Time is on the side of the proliferator," Bolton said. "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."

Bolton, who left office in September, has sparked the interest of Democrats in the impeachment of Trump over his alleged pressure campaign against Ukraine to investigate a political rival. Senate Majority Leader Mitch McConnell has rejected a request that he and other top aides be called to testify.

Contributing: Deirdre Shesgreen, David Jackson and William Cummings, USA TODAY

This article originally appeared on USA TODAY: John Bolton criticizes President Trump on North Korea denuclearization