North Korea Ramps Up Rhetoric Ahead of U.S. Nuclear Submarine Visit

North Korea threatened military action against American spy planes operating off the country’s east coast, its state media reported on Tuesday, as a United States submarine capable of shooting nuclear ballistic missiles planned to visit South Korea for the first time in four decades.

The North has often bristled at the United States’s military reconnaissance activities around the Korean Peninsula. But since Monday, it has issued three consecutive statements threatening retaliation against what it called “provocative aerial espionage” by American spy planes and drones.

On Monday, the North’s Ministry of National Defense accused an American strategic reconnaissance plane of illegally intruding into its “inviolable airspace” off its east coast​ this month​.

“There is no guarantee that such shocking accident as downing of the U.S. Air Force strategic reconnaissance plane will not happen,” it said, according to an English-language dispatch from the North’s official Korean Central News Agency.

In two separate statements​ issued​ later on Monday and early on Tuesday, Kim Yo-jong, the sister and spokeswoman for North Korea’s leader, Kim Jong-un, also said that American reconnaissance planes committed “a grave encroachment upon the sovereignty and security” of her country by flying over its 200-nautical mile economic water zone.

Ms. Kim warned that a “shocking” or “critical” incident would occur if such illegal intrusions continued.

​To drive home the threat, North Korea cited a 1969 incident in which it shot down an American EC-121 reconnaissance aircraft, killing all 31 people aboard.

Both the Pentagon and the South Korean military dismissed the North Korean statements as baseless accusations. But officials and analysts in the region fear that the North’s escalating rhetoric might lead to military provocations. ​

“We always operate responsibly and safely and in accordance with international law, so those accusations are just accusations,” Sabrina Singh, a deputy Pentagon press secretary, said on Monday. Matthew Miller, a U.S. State Department spokesman, urged North Korea to “refrain from escalatory actions.”

A country can claim the right to exploit marine resources in its so-called exclusive economic zone, which extends 200 nautical miles from its 12 nautical-mile territorial waters. But it does not hold sovereignty over the zone’s surface and the airspace above it.

South Korea also pushed back against the outbursts coming from the North.

“North Korea makes these claims for internal purposes and maybe to build ​an excuse to launch provocations,” Col. Lee Sung-jun, a South Korean military spokesman, said on Tuesday. He added that an exclusive economic zone guarantees the freedom of sailing and flying for foreign vessels and planes.

North Korea usually escalates anti-American rhetoric ahead of the July 27 anniversary of the end of the 1950-53 Korean War in order to instill in its people ​fear of the Americans and to justify its nuclear weapons program as a military deterrent to war.

In its statement, the North Korean defense ministry harshly criticized the Pentagon’s ​decision to send a nuclear-capable submarine to make a port call in South Korea “at some point in the future.” If the submarine arrives, it will be the first known visit to South Korea by a nuclear-capable American submarine since 1981.

When President Biden met his South Korean counterpart, Yoon Suk Yeol, in April, they agreed to strengthen the allies’ joint military drills and enhance the “regular visibility” of American strategic assets around ​Korea to highlight ​American commitment to defending South Korea.

The two leaders also agreed to establish a new group to discuss nuclear and strategic planning on the peninsula. The group’s first meeting is scheduled to take place in Seoul next Tuesday.

The North’s comments came as Mr. Yoon arrived in Lithuania on Monday to attend a North Atlantic Treaty Organization summit, where he was expected to join world leaders in condemning North Korea’s nuclear weapons development. North Korea’s nuclear threat will also likely become a topic of discussion when foreign ministers from around the world attend the annual gatherings led by the Association of Southeast Asian Nations, which are taking place in Jakarta, Indonesia, later this week.

North Korea​ usually turns more ​defiant ahead of such international gatherings.