The arrival of the USS Missouri, also known as SSN-780, comes after South Korea and the U.S. held their second Nuclear Consultative Group meeting in Washington on Friday.

“Any nuclear attack by North Korea against the United States or its allies is unacceptable and will result in the end of the Kim regime,” a joint U.S.-South Korean statement from the meeting said.

A senior South Korean official said earlier this week that North Korea may test-launch an intercontinental ballistic missile this month.

Visits by U.S. nuclear submarines had previously been rare, but they have increased under agreements between Seoul and Washington that increased the arrivals of U.S. military assets to help deter North Korea. Another U.S. nuclear-powered submarine, the USS Santa Fe, called at a port on the South Korean island of Jeju in November.

The USS Carl Vinson, a U.S. aircraft carrier, also arrived at a Busan port last month in the effort to increase deterrence against North Korea’s nuclear and missile programs.