South hopes to deploy key U.S. military assets

South Korea’s military said Monday it will seek to deploy U.S. strategic assets such as nuclear-powered aircraft carriers and strategic bombers, while leaving open the possibility of bringing back tactical nuclear weapons.

National Defense Minister Song Young-moo relayed the plan during an urgent briefing to lawmakers on the parliamentary National Defense Committee, but did not say when or how relevant talks would be held.

Song, who returned from a business trip to Washington last Saturday, said he asked U.S. Secretary of Defense James Mattis to deploy strategic assets in South Korea on a “regular basis.”

Washington has not officially announced whether it will deploy the assets to South Korea, but a South Korean government official who recently briefed local reporters on the talks said Mattis “expressed his agreement” during their discussion.

A strategic asset refers to arms systems intended to destroy targets crucial to carrying out a war, such as a military base or a defense industry infrastructure. Nuclear-powered aircraft carriers and nuclear-armed submarines are among such assets, the closest from the United States to South Korea being those in Guam, located some 2,000 miles away in the Western Pacific.

On the possibility of deploying U.S. tactical nuclear weapons to South Korea, Song said it “could be one option,” but quickly added that the allies “will have to give further thought” because it was a “difficult” issue.

Regarding Sunday’s nuclear test, the Defense Ministry claimed the bomb had a yield of about 50 kilotons, which would make it the strongest to date and nearly five times more powerful than North Korea’s most previous nuclear experiment on Sept. 9, 2016. A yield of 1 kiloton is equivalent to 1,000 tons of TNT.

The atomic bombs dropped on Japan’s Hiroshima and Nagasaki during World War II had a yield of 15 and 21 kilotons, respectively. South Korea’s calculation of 50 kilotons is based on the assessment that the nuclear test set off a 5.7-magnitude earthquake. The United States Geological Survey and China’s Network Earthquake Center measured the magnitude of the event at 6.3, which would mean the bomb could have had a far larger yield.

Local military officials did not confirm whether North Korea actually tested a hydrogen bomb, as it claimed Sunday, saying only that “several nuclear materials were incorporated.” Seoul denied Pyongyang’s statement last year, when it claimed to have detonated a hydrogen bomb in its fourth nuclear test on Jan. 6, 2016.

In the Monday briefing, the military said North Korea’s first and second nuclear tests were plutonium bombs, while the rest were plutonium or highly enriched uranium.

Military officials also mentioned detecting signs that Pyongyang was preparing another missile launch, saying the regime appears to be fully equipped for an intercontinental ballistic missile (ICBM) test, which would be the third of its kind.

North Korea carried out two ICBM tests in July, on the 4th and 28th. On Monday, while bragging about its “absolutely successful” sixth nuclear test, the North claimed that the weapon could be miniaturized and loaded onto an ICBM, apparently threatening to target the United States.

Suh Hoon, director of South Korea’s National Intelligence Service, echoed the possibility of an imminent missile test during a separate parliamentary briefing Monday to lawmakers on the Intelligence Committee, saying reports showed that the country could be preparing to test a new submarine-launched ballistic missile or an intermediate-to-intercontinental range ballistic missile.

BY LEE SUNG-EUN [lee.sungeun@joongang.co.kr]