The U.S. and South Korea plan to hold large-scale military drills in a move set to anger Pyongyang, which has promised an unprecedented response to the exercises and threatened to turn the Pacific Ocean into its “firing range.”

The two allies will hold their “Freedom Shield” exercise from March 13-23, which will bolster a “joint defense posture in the face of North Korea’s nuclear and missile threat,” the militaries from the U.S. and South Korea said Friday in a statement.

The drills would feature large-scale joint outdoor movement training, including joint landing training and reflect “modified security environments” as a result of North Korean advancements in its missile and nuclear arms capabilities, the statement said.

Kim Yo Jong, the influential sister of the North Korean leader, last month in a speech to the ruling party, threatened retaliation against joint drills by saying “there is no change in our will to make the worst maniacs escalating the tensions pay the price for their action.”

She also made the “firing range” comment, hinting the state could start testing whether its warhead designs can withstand the heat of reentering the atmosphere.

The last time North Korea launched a missile into the Pacific was October 2022, when it fired a Hwasong-12 intermediate-range ballistic missile over Japan, flying 4,600 kilometers (2,860 miles), and marking the longest distance traveled by a North Korean missile to date.

South Korean President Yoon Suk Yeol, who took office in May, brought back joint military exercises with his country’s U.S. ally. The drills had been scaled down or halted under former President Donald Trump, who was hoping the move would facilitate his nuclear negotiations with North Korean leader Kim Jong Un.

Trump’s three meetings with Kim from 2018, however, led to no concrete steps to wind down Pyongyang’s nuclear program, which only grew in strength and size as the in-person diplomacy eventually fizzled.

North Korea for decades has called the joint exercises a prelude to an invasion and nuclear war. Last month, it test fired an intercontinental ballistic missile designed to deliver a nuclear warhead to the American mainland a day after its Foreign Ministry threatened the U.S. with “unprecedentedly persistent and strong counteractions” for holding joint military exercises with South Korea.

Japan, which North Korea has listed as one of its mortal enemies, has joined several drills with the U.S. in South Korea in recent months but there was no indication if its military would take part in the upcoming exercises.