U.S. intelligence shows there could be a North Korean nuclear test, or a long-range missile test, or both, before, during or after President Joe Biden's trip to South Korea and Japan starting this week, White House national security adviser Jake Sullivan said Wednesday.
The White House said Biden would not visit the Demilitarized Zone that divides North and South Korea during his visit to South Korea, which begins Friday, having said last week he was considering such a trip.
"Our intelligence does reflect a genuine possibility that there will be either a further missile test, including long-range missile test, or a nuclear test, or frankly both, in the days leading into, on or after the president's trip to the region," Sullivan told a White House briefing.
"We are preparing for all contingencies," he said.
Sullivan said that the United States was coordinating closely with South Korea and Japan and that he had also discussed North Korea with a senior Chinese diplomat in a phone call Wednesday.
Biden's trip, which is to run through Tuesday, will be his first to Asia as president. It will include his first summit with South Korean President Yoon Suk Yeol, who took office May 10 and has vowed to take a harder line against North Korean "provocations."
Sullivan said the United States was prepared to make both short- and longer-term adjustments to its military posture as necessary "to ensure that we are providing both defense and deterrence to our allies in the region and that we're responding to any North Korean provocation."
Earlier, U.S. and South Korean officials said North Korea appeared to be preparing to test an intercontinental ballistic missile ahead of Biden's trip to South Korea, even as it battled a big COVID-19 outbreak.
South Korean deputy national security adviser Kim Tae-hyo said such a test appeared imminent and a U.S. official said it could happen as soon as Thursday or Friday.
Kim Tae-hyo said a "Plan B" had been prepared in the event of a small or large North Korean "provocation," which could involve altering the summit schedule.
A weapons test could overshadow Biden's broader trip focus on China, trade and other regional issues, and underscore the lack of progress in denuclearization talks with North Korea, despite his administration's vow to break the stalemate with practical approaches.
North Korea has conducted repeated missile tests since Biden took office last year and this year resumed launches of ICBMs for the first time since 2017. After each launch, Washington has urged North Korea to return to dialog, but to no response.
Meanwhile, U.S. efforts to encourage tougher international sanctions have met Russian and Chinese resistance.
Analysts say that while China's view on sanctions might alter with another nuclear test, Russian support appeared unlikely after the campaign of U.S.-led sanctions over Moscow's Ukraine intervention.
Yoon is expected to seek greater assurances from Biden that Washington will strengthen "extended deterrence" against North Korea — a reference to the U.S. nuclear weapons umbrella protecting its allies.
Yoon's administration has asked Washington to station more nuclear-capable "strategic assets," such as long-range bombers, submarines and aircraft carriers in the region.
Kim said the chances that North Korea would conduct a nuclear test this weekend appeared low, but if it staged any major provocation, such assets were ready to be mobilized.
A nuclear test could complicate international efforts to offer Pyongyang help to deal with its COVID crisis.
Yoon has offered to help North Korea with this issue, and analysts expect Biden to endorse this effort, even though his administration has said it has no plans to send vaccines directly to North Korea and Pyongyang has persistently refused help though the global vaccine initiative.
The World Health Organization is worried that the rising caseload and a lack of modern care for COVID-19 in North Korea could give rise to deadlier new variants.
North Korea sent aircraft to China to pick up medical supplies days after it confirmed the outbreak, media reported Tuesday.
A new report by Washington's Center for International and Strategic Studies said commercial satellite imagery showed work continuing at North Korea's main nuclear site, where underground testing tunnels were shuttered in 2018 after leader Kim Jong Un declared a moratorium on nuclear and ICBM tests.
He has since said he is no longer bound by that moratorium because of a lack of progress in talks with the United States. While North Korea has resumed ICBM testing, it has not tested a nuclear bomb since 2017.
North Korea has also resumed construction at a long-dormant nuclear reactor that would increase its production of plutonium for nuclear weapons by a factor of 10, researchers at the U.S.-based James Martin Center for Nonproliferation Studies reported last week, citing satellite imagery.
Earlier Wednesday, Sullivan discussed the possibility of North Korean nuclear or missile tests with China's top diplomat, Yang Jiechi, during a call focused on regional security issues and nonproliferation.
Sullivan did not provide further details about the call, but the White House said in a statement that he and Yang had discussed Russia's war against Ukraine and "specific issues in U.S.-China relations."
Sullivan and Yang last met in Rome in March, ahead of Biden's call that month with Chinese leader Xi Jinping, during which the U.S. president warned Xi of consequences should Beijing offer material support for Moscow's war in Ukraine.
China has refused to condemn Russian President Vladimir Putin's actions and has criticized sweeping Western sanctions on Russia, but senior U.S. officials say they have not detected overt Chinese military and economic support for Russia.
The United States, India, Australia and Japan agreed in March that what is happening to Ukraine should not be allowed to happen in the Indo-Pacific, an oblique reference to the democratic island of Taiwan, which Beijing claims as its territory.
"If the U.S. side persists in playing the 'Taiwan card' and goes further down the wrong path, it will surely put the situation in serious jeopardy," Xinhua cited Yang as telling Sullivan.
Yang added that China would take "firm actions" to safeguard its sovereignty and security interests, Xinhua said.