The South Korean Navy on Friday received the first submarine capable of transporting ballistic missiles, designed to counter the threat of underwater missiles from the nuclear-armed North Korea.
For several years, Pyongyang has been developing sea-to-surface ballistic missiles.
In January, during a military parade in the presence of North Korean leader Kim Jong Un, Pyongyang launched four missiles with black and white warheads.
The North Korean news agency confirmed at the time that "the ability of its strike can completely eliminate the enemies (...) outside the territory."
A few days ago, Kim told the ruling party congress that his country had finished plans to build a nuclear submarine. It is likely that such a submarine will not become operable before several years.
A submarine-launched ballistic missile could allow Pyongyang to change its strategy, with the possibility of launching a surprise attack near the United States or carrying out a strike even without ground forces.
South Korea organized a launch ceremony for its submarine on Geoje Island, the navy said in a statement.
The submarine, designed by South Korea itself, weighs 3,000 tons and runs on diesel, is 83.5 meters long and 9.6 meters wide, and can stay underwater for 20 days without returning to the surface of the water.
The navy said in the statement that the submarine would be an added value "to defend our sea and its mere presence would frighten" the enemy.
The submarine, equipped with six vertical launch tubes capable of launching underwater ballistic missiles, will be ready for operation in August 2022, according to military authorities.
North Korea is also seeking to enhance its underwater power.
In 2019, Kim Jong Un inspected a newly built submarine and appeared in pictures standing next to it.
Friday´s ceremony comes days after the North Korean leader´s sister described Seoul as "treacherous" because of South Korea´s joint military exercises with the United States. The two allies warned that they would face greater security threats as a result.
The United States has about 28,500 troops in South Korea under a defense treaty against North Korea, which has a nuclear arsenal.
