The United States and South Korea wrapped up a four-day series of naval drills Sunday amid mounting tensions with North Korea’s Kim Jong Un regime.

Newsweek reached out to the North Korean embassy in Beijing and the U.S. Indo-Pacific Command via email for comment.

Why It Matters

North-South relations are at their lowest point in decades as Pyongyang pushes ahead with its ballistic missile and nuclear weapons programs. Kim’s decision to send thousands of troops to fight alongside Russian forces in Ukraine has only escalated the standoff.

The 41-year-old leader has cited Seoul’s growing military ties with Washington, and increasingly, with Tokyo, as justification for his nuclear arsenal, saying it’s needed to defend against these “provocations.”

What To Know

South Korea’s Yonhap News Agency cited officials as saying the U.S. and South Korea’s Thursday-to-Sunday drills, collectively known as the Maritime Counter Special Operations Exercise (MCSOFEX), were aimed at strengthening the allies’ ability to counter simultaneous attacks.

The exercise featured simulated operations across multiple domains of warfare, including scenarios involving North Korean forces infiltrating across the de facto maritime border, and drills focused on simulated surface, submarine and aerial attacks.

Other elements focused on intercepting drones and countering proliferation of weapons of mass destruction.

US and South Korean Navies Conduct Drill

Arleigh Burke-class guided-missile destroyer the USS William P. Lawrence conducts a drill with South Korea’s Navy as part of the allies’ Maritime Counter Special Operations Exercise in early May 2025.
Arleigh Burke-class guided-missile destroyer the USS William P. Lawrence conducts a drill with South Korea’s Navy as part of the allies’ Maritime Counter Special Operations Exercise in early May 2025.
Mass Communication Specialist 3rd Class Gavin Arnold Hendershot/U.S. Navy

Participating U.S. forces included the Arleigh-Burke-class guided-missile destroyer USS William P. Lawrence and a maritime patrol aircraft, according to South Korean naval officials. South Korea contributed roughly 10 aircraft and 10 warships, including the destroyer ROKS Yulgok Yi I.

As the drills got underway Thursday, North Korea fired multiple ballistic missiles over the Sea of Japan, in what South Korean military officials said may have been a demonstration intended to promote foreign arms sales.

Last month, Pyongyang conducted the first test-firing of its largest warship, a 459-foot-long destroyer it said was equipped with the “most powerful weapons.

What People Are Saying

The U.S. Navy wrote in a statement: “MCSOFEX is a high profile exercise focused on readiness and shaping the maritime domain to achieve both U.S. and ROK cooperation objectives.”

North Korea’s state-run Korean Central News Agency wrote Sunday: “The U.S. and its vassal states are staging a series of nuclear operation drills on the Korean peninsula and in its vicinity after making a nuclear war against the Democratic People’s Republic of Korea a fait accompli…This reckless act of aggravating the situation requires that the armed forces of the DPRK maintain a rapid reaction capability and thoroughgoing war posture.”

What Happens Next

The U.S., South Korea, and Japan are likely to continue strengthening defense ties, prompting further North Korean demonstrations of displeasure.

Officials from the three countries pledged to “continue to maintain the momentum of trilateral security cooperation” during the latest meeting of their Defense Trilateral Talks Working Group in Seoul in late April.