SEOUL — North Korea said on Sunday that President Biden had made “a big blunder” by calling its nuclear arsenal a threat last week, and it warned that the United States would face “a very grave situation” if it maintained its “hostile policy” toward Pyongyang.
The statement, attributed to a senior official, was one of three that the North released on Sunday directed at the United States and its ally South Korea. They included warnings that the North might respond to the Biden administration’s recent statements about the country with unspecified “corresponding measures.”
Mr. Biden made a brief reference to North Korea in his speech before a joint session of Congress on Wednesday, saying that its nuclear program and Iran’s presented “serious threats to American security and the security of the world.” He said the United States and its allies would deal with them “through diplomacy as well as stern deterrence.”
“It is certain that the U.S. chief executive made a big blunder,” Kwon Jong-gun, a senior official at North Korea’s Foreign Ministry, said in a statement published by the North’s state news media. He said Mr. Biden’s remark “clearly reflects his intent to keep enforcing the hostile policy toward” North Korea.
“We will be compelled to press for corresponding measures, and with time the U.S. will find itself in a very grave situation,” he said.
North Korea has long said that it will not give up its nuclear arsenal until the United States changes its “hostile” policy. It has doubled down on that insistence since direct talks between its leader, Kim Jong-un, and President Donald J. Trump ended in 2019 with no agreement on dismantling the North’s nuclear weapons facilities or easing American-led sanctions imposed on the North.
On March 25, North Korea launched two short-range ballistic missiles, its first such test in a year. Analysts have since warned that the North could carry out more tests or other provocations in an attempt to bolster its leverage in any talks with the Biden administration.
The administration, which has been conducting a North Korea policy review, recently indicated that it would pursue a strategy somewhere between Mr. Trump’s direct outreach to Mr. Kim, in which he strove for a single, sweeping deal, and the “strategic patience” approach of former President Barack Obama, which sought to compel the North to negotiate through sanctions and other forms of pressure. Both approaches failed, and North Korea has kept expanding its arsenal.
The White House press secretary, Jen Psaki, said on Friday that the administration “will not focus on achieving a grand bargain, nor will it rely on strategic patience.” She said it would seek “a calibrated, practical approach that is open to and will explore diplomacy” with North Korea and would try to “make practical progress that increases the security” of the United States and its allies.
In his Sunday statement, Mr. Kwon said that the administration’s talk of diplomacy was “a spurious signboard for covering up its hostile acts.”
In a separate statement on Sunday, also released through the state news media, the North’s Foreign Ministry accused the administration of using criticism of the North’s human rights record as “a political weapon for overturning our social system.”
“We will be forced to take corresponding measures,” an unidentified spokesman for the ministry was quoted as saying. “We have already made it clear that we will counter in the strongest terms whoever encroaches upon the dignity of our supreme leadership, which is more valuable than our lives.”
That was in response to a statement last week by Ned Price, the State Department spokesman, who called North Korea “one of the most repressive and totalitarian states in the world.” Mr. Price cited “shoot-to-kill orders at the North Korea-China border” that American officials say the North has imposed since the emergence of Covid-19.
Also on Sunday, Mr. Kim’s sister, Kim Yo-jong, denounced South Korea for failing to stop a group of activists from using balloons to send propaganda leaflets across the countries’ border into the North.
Such launches, a tactic often used by defectors from North Korea campaigning against the Kim regime, were banned by South Korea in March, on the grounds that they needlessly provoked Pyongyang and endangered South Koreans living near the border. The North cited the propaganda launches last year when it blew up an office building on its soil where officials from both Koreas had worked together.
Park Sang-hak, who leads a defectors’ group in Seoul, said on Friday that his organization had defied the launch ban earlier in the week, releasing 10 large balloons carrying a half million leaflets. He accused the South Korean government of “gagging” the defectors and denying North Koreans the right to know how their leaders were seen by the outside world.
Ms. Kim, who serves as her brother’s spokeswoman on inter-Korean issues, called the defectors “human wastes” in her statement Sunday, characterizing the launch as “a serious provocation” and warning that the North would “look into corresponding action.”