The Democratic People's Republic of Korea (DPRK), on Tuesday, condemned the arrival of a US Navy nuclear submarine in South Korea, warning it would use "any defense means" to protect itself, according to state-run media.

In a statement, the Defense Ministry called the deployment a "concentrated expression of the US’ unchangeable madness toward DPRK."

"We express grave concern over the dangerous hostile military actions of the United States that could push the acute military standoff on the Korean Peninsula into an actual armed conflict," the statement added, urging Washington to halt "provocative acts that lead to further instability."

This came a day after the USS Alexandria, a Los Angeles-class attack submarine, arrived in the South Korean port city of Busan for resupply and crew rest. It marked the first US nuclear submarine visit to the peninsula this year.

Pyongyang said its armed forces are closely monitoring US military movements and are prepared to take any necessary measures to safeguard national security.

"We will not back down an inch from our confrontation with this tyrannical enemy," the statement concluded.

On Saturday, DPRK leader Kim Jong Un reaffirmed his commitment to expanding the country’s nuclear forces, accusing the US of fueling global conflicts.

"The US stands unfailingly behind the world’s big and small disputes and tragedies of bloodshed," Kim said, adding that this justifies Pyongyang’s pursuit of an "unlimited defense capability."

His remarks followed recent comments by President Donald Trump suggesting that Washington would maintain relations with DPRK.

DPRK says nuclear arsenal 'non-negotiable red line'

In a related context, DPRK reaffirmed that its nuclear arsenal is a "red line" that cannot be negotiated or relinquished, emphasizing that it is designated for actual military use if the country’s sovereignty or the safety of its people is threatened.

In an official statement released on Saturday by the Korean Central News Agency (KCNA), the DPRK condemned NATO and the European Union for refusing to recognize the DPRK as a nuclear power.

The statement described calls for the complete dismantling of Pyongyang’s nuclear program as "irrational remarks."

KCNA asserted that the DPRK's nuclear capabilities were not merely a political issue but served as a strategic deterrent against threats from hostile forces.

Pyongyang further stressed that it will not place nuclear disarmament on the negotiation table, even if dialogue with the United States resumes.