North Korea blames US-South Korea military drill for postponement of talks

The North's message was "regrettable," the Unification Ministry said.

North Korea surprised Seoul with a message around midnight that it intends to postpone indefinitely high-level talks that were scheduled for today.

South Korea's Defense Ministry responded by saying the Max Thunder training would continue as scheduled, while the Unification Ministry said in a statement the North's message was "regrettable."

"North Korea is back to its old game of trying to raise the stakes prior to a meeting. But Kim risks undermining the goodwill he had built up through his diplomatic outreach since January."

North Korea earlier threatened to pull out of a planned summit with the United States if Trump or officials demanded a "unilateral" abandonment of its nuclear arsenal, driving Kim Jong Un's nation "into a corner."

"The U.S. is miscalculating the magnanimity and broad-minded initiatives of the DPRK as signs of weakness and trying to embellish and advertise as if these are the product of its sanctions and pressure," Kim Kye Gwan, North Korea's first vice minister for foreign affairs and former nuclear-program negotiator, said.

Kim Kye Gwan accused "high-ranking officials of the White House and the Department of State" of "provoking" them with "unbridled remarks."

Bolton recently said the administration is considering a roadmap for North Korea similar to Libya.

North Korea's statement was "very aggressive" -- too aggressive to be regarded as "just a symbolic gesture or just a hint to the U.S. saying you guys need to slow down," Sue Mi Terry, a senior fellow and Korea chair at the Center for Strategic International Studies, said.

“If this is a calculation by Kim Jong Un to gain leverage in the upcoming talks with President Trump," Terry said today at the leadership conference in Seoul. "I think he might be miscalculating pouring cold water."

Analysts who track North Korea said the nation was sensitive to the Libya comparison, especially after what happened to that country's deposed leadership.

Bolton has previously said it would be "perfectly legitimate" to carry out a preemptive strike on North Korea. His appointment in March raised concerns among those in favor of reconciliation.

The North Koreans also appear sensitive to recent comments by Secretary of State Mike Pompeo about economic opportunities available to the North if they denuclearize, according to Jung H. Pak, the SK-Korea Foundation Chair in Korea Studies and a senior fellow at the Brookings Institution.

"They are annoyed and irritated about the supposed carrot that we're throwing out there they didn’t even ask for," Pak said today at the leadership conference in Seoul. "It portrays them as a supplicant rather than equal negotiating partner that they want."

Still, this sudden turn by Pyongyang, especially after Kim Jong Un just stepped foot in South Korea, shows the North's frustration at U.S. posturing and the ongoing military drills.

The North had no choice but to put a stop to the inter-Korean high-level talks, blaming that South, which is "completely responsible" for "playing around in madness" when relations potentially had been heading toward peace, according to North Korean state news agency KCNA.

The South's Unification Ministry said in a statement, "It is regrettable that North unilaterally put off the inter-Korean high-level talks on the grounds of annual air-combat drills," adding that it would send a notice to the North today, perhaps to reschedule talks.

It was unclear exactly what message would be included.

ABC News' Hakyung Kate Lee, Jaesang Lee and Jiweon Park contributed to this report.