South Korean and U.S. soldiers are on guard against simulated enemy forces as they search a building during an urban area operation drill of South Korea and the United States' joint annual military exercise Freedom Shield in Paju, Gyeonggi Province, March 19. Yonhap

South Korea and the United States wrapped up a major annual combined military exercise aimed at bolstering their defense capabilities against North Korean military threats Thursday, the South's military said.

The computer-simulated Freedom Shield exercise drew to an end after an 11-day run in the face of North Korea's evolving nuclear and missile threats and deepening military cooperation with Russia.

This year's exercise marked the first major military exercise by the allies since U.S. President Donald Trump returned to office in January, with the U.S. military having reaffirmed its security commitment to South Korea.

For this year's exercise, South Korea deployed some 19,000 troops, and the allies staged expanded on-field drills to enhance their interoperability, the South's Joint Chiefs of Staff (JCS) said.

The exercise involved drills across the land, sea, air cyber and space domains, with South Korea's Strategic Command and the naval Task Fleet Command joining the joint exercise for the first time.

"By reflecting realistic threats, such as changes in the North Korean military's strategy, tactics and forces, learned from Russia and North Korea's military cooperation and various armed conflicts, South Korea and the U.S. could enhance the alliance's combined defense posture and response capabilities through realistic training," the JCS said.

JCS Chairman Adm. Kim Myung-soo held in-depth discussions with the chief of the Combined Forces Command (CFC) on the impact of Pyongyang and Moscow's military cooperation on the Korean Peninsula, it added.

"We will maintain a firm readiness posture to sustain stability and peace on the Korean Peninsula," Kim was quoted as saying.

Gen. Xavier Brunson, commander of the U.N. Command, CFC and U.S. Forces Korea, echoed the view.

"Exercises like Freedom Shield 25 ensure that our forces remain ready to respond to any threat, reaffirming our shared commitment to regional security," Brunson said in a release.

In a separate post updated on X, formerly Twitter, on Thursday, the U.S. general stressed that the "alliance is ironclad and our combined force is ready."

North Korea has long condemned the allies' joint drills as a rehearsal for an invasion against and has a track record of staging weapons tests in response.

The North released a barrage of statements denouncing the joint drills as a "dangerous provocative act" and fired several ballistic missiles, believed to be close-range ones, on the first day of the exercise. But it did not carry out major provocations, such as the firing of a long-range ballistic missiles, this year.

Compared with North Korea's reaction to the allies' springtime exercises in 2023 and 2024, the level of its military responses to this year's drills was assessed as relatively low, while it issued more rhetoric denouncing Freedom Shield, according to Seoul's unification ministry.

"At a time when North Korea has dispatched troops to Russia and there is talk of a ceasefire for Moscow's war with Ukraine, heightened external uncertainty appears to be a major factor (that affected North Korea's behavior)," a ministry official said on condition of anonymity.

Freedom Shield is one of the allies' two major annual exercises that train troops based on an all-out war scenario. The other exercise — Ulchi Freedom Shield — usually takes place in August.

South Korea and the U.S. have maintained that such drills are defensive in nature. (Yonhap)