SEOUL: The US has started to deploy the Terminal High Altitude Area Defense (THAAD) anti-missile system to South Korea, US Pacific Command said in a statement on Tuesday (Mar 7).
The system will be deployed to counter ongoing nuclear and ballistic missile tests from North Korea, the statement said.
"Continued provocative actions by North Korea, to include yesterday's launch of multiple missiles, only confirm the prudence of our alliance decision last year to deploy THAAD to South Korea," US Pacific Commander Admiral Harry Harris said in the statement.
"North Korea's accelerating program of nuclear weapons tests and ballistic missile launches constitute a threat to international peace and security, and are in violation of multiple United Nations Security Council resolutions."
Last year, South Korea and the US agreed to install the THAAD system, which China has repeatedly denounced as a threat to its security.
The statement from the Pacific Command, which oversees US military operations in the Asia-Pacific, pointed out that the system is "a strictly defensive capability and it poses no threat to other countries in the region".
The system is meant to intercept and destroy short- and medium-range ballistic missiles during their final phase of flight.
The move by the US military is likely to deepen the brewing conflict between South Korea and China, which has angrily opposed the THAAD deployment as destroying the regional security balance.
The four ballistic missiles landed in the sea off Japan's northwest, angering Seoul and Tokyo, days after North Korea promised retaliation over the military drills which it sees as preparation for war.
US President Donald Trump and Japanese Prime Minister Shinzo Abe discussed the launches during a phone call on Tuesday.
"Japan and the US confirmed that the latest North Korean missile launches were clearly against UN resolutions and a clear provocation against the regional and international community," Abe told reporters. "(North Korea's) threat has entered a new phase."
Trump also spoke to South Korea's acting President Hwang Kyo-ahn to discuss the North's missile launches, Hwang's office said.
The missile test was undertaken by an army unit commissioned with attacking US military bases in Japan, the North's official KCNA news agency said.
"In the hearts of artillerymen ... there was burning desire to mercilessly retaliate against the warmongers going ahead with their joint war exercises," KCNA said.
"He (Kim) ordered the KPA Strategic Force to keep highly alert as required by the grim situation in which an actual war may break out any time, and get fully ready to promptly move, take positions and strike so that it can open fire to annihilate the enemies."
South Korea said the missiles North Korea fired on Monday were unlikely to have been intercontinental ballistic missiles (ICBM), which can reach the US. They flew on average 1,000km and reached an altitude of 260km.
Some landed as close as 300km from Japan's northwest coast, Japan's Defence Minister said earlier.
The US and Japan have requested a United Nations Security Council meeting on the launches, which will likely be scheduled for Wednesday, diplomats said.
The planned installation of the US anti-missile defence system, which South Korea has said will be operational by the end of the year, has led to a diplomatic standoff between China and South Korea.
Chinese authorities have closed nearly two dozen retail stores of South Korea's Lotte Group that approved a land swap with the country's military last week to allow it to install the system.
China objects to the THAAD deployment, saying its territory is the target of the system's far-reaching radar. South Korea and the US have said the missile system is aimed only at curbing North Korean provocations.