North Korean leader Kim Jong Un is hinting that the goodwill established with the United States in 2018 may not continue into 2019.
In his New Year's Day address Tuesday, Kim said he would be willing to hold another summit with President Donald Trump, but demanded sanctions relief.
"If the U.S. fails to carry out its promise to the world ... and remains unchanged in its sanctions and pressure upon the DPRK, we might be compelled to explore a new path for defending the sovereignty of our country and supreme interests of our state," Kim warned.
Most of his New Year speech focused on the moribund North Korean economy and his desire to improve the lives of its citizens — a task that is nearly impossible if trade with North Korea is severely limited.
Kim expressed a "firm will" that North Korea will no longer produce or test nuclear weapons or "use or spread" its arsenal.
Negotiations between the United States and North Korea have stalled since the June summit in Singapore.
Trump has reportedly questioned why the U.S. has provided the lion's share of the cost of the military alliance and defense of South Korea and has asked Seoul to contribute significantly more. Trump has also questioned the need for U.S. forces on the Korean peninsula.
There were several diplomatic breakthroughs between Pyongyang and South Korea in 2018 — a sign that the South could be moving away from the U.S. and more toward the North — something that would more than please Kim.
Former U.S. Acting Assistant Secretary of State Evans Revere — who has spent many hours negotiating with North Korea — says the U.S. is sailing in uncharted and potentially dangerous waters in Korea.
"The statement by the North Koreans that they might seek a new path for a new way to defend their country's sovereignty, I think, is a pretty explicit reference to their preparedness to resume nuclear and ballistic missile testing in the coming months if things do not go their way," Revere said. "It's an attempt to blackmail the United States."
Revere said the U.S. and North Korea have different definitions of the word "denuclearization." He said Washington applies it to the North while Pyongyang believes it applies to the entire Korean peninsula.
He said the North "is tired of hearing Secretary [of State] Pompeo and other members of the administration talk about denuclearization as the U.S. defines it."
There has been no official reaction to Kim's speech from the State Department or White House.
Ira Mellman contributed to this report.