South Korean President Yoon Suk-yeol has inspected a US nuclear-capable submarine in the southeastern port city of Busan to underscore the two countries' deterrence against North Korea.

The USS Kentucky, a nuclear-powered submarine capable of carrying ballistic missiles equipped with nuclear warheads, arrived in Busan on Tuesday.

Yoon visited the naval base in Busan on Wednesday. He told US and South Korean military personnel that with the deployment of US strategic assets, "We will make North Korea not even dream of carrying out a nuclear provocation."

He added, "We warned that should North Korea carry out a provocation, it will lead to the end of its regime."

Yoon later boarded the submarine with his wife, Kim Keon-hee, and received a briefing from the US side.

The USS Kentucky's visit is based on an agreement at the US-South Korea summit in April.

It is the first call at a South Korean port since 1981 by a US nuclear-powered submarine capable of carrying ballistic missiles equipped with nuclear warheads.

It is unusual for the activities of such submarines to be disclosed, as they are considered one of the three pillars of US nuclear deterrence, along with intercontinental ballistic missiles and strategic bombers.

In Seoul on Tuesday, the US and South Korea held the first meeting of the Nuclear Consultative Group, which aims to strengthen Washington's "extended deterrence." The term refers to its commitment to defend its allies with nuclear weapons and other capabilities.