South Korean Yonhap news agency reported on Thursday, citing Seoul's military, that the USS Michigan, a US Ohio-class strategic nuclear-powered guided missile submarine, took part in joint drills with the South Korean navy during the stay in the country in line with the so-called "Washington Declaration".

USS Michigan arrived at the Korean Peninsula on June 16, the day after the DPRK launched two short-range ballistic missiles toward the Sea of Japan.

The submarine is set to leave South Korea this Thursday. This is the first time since October 2017 that the United States has sent a submarine of this class to South Korea.

South Korean Defense Ministry Spokesperson, Jeon Ha-kyu, told reporters that the submarine took part in the joint special operations training with the South Korean navy during its stay in the country, without providing details.

In April, the leaders of South Korea and the United States adopted the Washington Declaration that provides for the establishment of a regular bilateral consultation mechanism on extended deterrence and strategic planning.

South Korea secured a US promise to promptly deploy "the entire force of the alliance," including nuclear weapons, in the event of an alleged nuclear attack by the DPRK.

Washington also assured Seoul it would use all measures, including nuclear weapons, in the case of an alleged attack from Pyongyang, and promised to send nuclear missile submarines to the Korean Peninsula.

A couple of days ago, DPRK state media reported that the country launched an important political summit with leader Kim Jong Un in attendance to discuss strengthening the country's economy and evaluating security measures in light of the US provocative step of sending nuclear submarines to South Korea.

Since March, the US and South Korea have undertaken large-scale joint military drills, simulating large-scale bombing against the DPRK. Pyongyang has condemned the allies’ combined exercises as invasion rehearsals.