SEOUL, South Korea >> The influential sister of North Korean leader Kim Jong Un warned Tuesday that it’s ready to take “quick, overwhelming action” against the United States and South Korea, as the two countries are expanding their regular military drills.

Kim Yo Jong’s statement came a day after the United States flew a nuclear-capable B-52 bomber to the Korean Peninsula for a joint drill with South Korean warplanes. The U.S. and South Korean militaries are also preparing to revive their largest field exercises later this month.

“We keep our eye on the restless military moves by the U.S. forces and the South Korean puppet military and are always on standby to take appropriate, quick and overwhelming action at any time according to our judgment,” Kim Yo Jong said in a statement carried by state media.

She didn’t elaborate on what action North Korea would take. But North Korea has often performed missile tests in response to U.S.-South Korean military drills because it views them as an invasion rehearsal.

“The demonstrative military moves and all sorts of rhetoric by the U.S. and South Korea, which go so extremely frantic as not to be overlooked, undoubtedly provide (North Korea) with conditions for being forced to do something to cope with them,” she said.

Monday’s flyover of the B-52 bomber was the latest in a series of U.S.-South Korean aerial exercises involving powerful U.S. aircraft. The U.S. has deployed a long-range U.S. B-1B bomber or multiple B-1Bs to the peninsula a few more times earlier this year. South Korea said those drills demonstrated the allies’ ability to make a decisive response to potential North Korean aggressions.

Last Friday, the South Korean and U.S. militaries announced they would conduct a computer-simulated command post training from March 13-23 and restore their largest springtime field exercises that were last held in 2018.

The allies had canceled or scaled back some of their regular drills since 2018 to support now-dormant diplomacy with North Korea and guard against the COVID-19 pandemic. But they’ve been restoring their exercises after North Korea last year conducted a record number of missile tests and openly threatened to use its nuclear weapons in potential conflicts with its rivals.

In a separate statement Tuesday, North Korea’s Foreign Ministry called the flyover of the U.S. B-52 bomber “a reckless military provocation” that it said pushes the situation on the peninsula “deeper into the bottomless quagmire.”

An unidentified head of the ministry’s foreign news office said the recent U.S. military actions foretell “the gravity of the catastrophic tension that will be entailed by them.”

“There is no guarantee that there will be no violent physical conflict in the Korean Peninsula,” if the U.S.-South Korean military provocation continues, the official said.

North Korea often unleashes fiery rhetoric in times of heightened animosities with the United States and South Korea. Possible steps North Korea could take include a nuclear test or the launch of a new type of intercontinental ballistic missile targeting the mainland U.S., observers say.

Last month, Kim Yo Jong threatened to turn the Pacific into the North’s firing range. In her Tuesday statement, she said North Korea would consider a possible U.S. attempt to intercept a North Korean ICBM a declaration of war. She cited a South Korean media report saying the U.S. military plans to shoot down a North Korean ICBM if it’s launched toward the Pacific.

All known North Korean ICBM tests have been made at steep angles to avoid neighboring countries, and the weapons landed in the waters between the Korean Peninsula and Japan.