North Korea has fired a submarine-launched ballistic missile, the South Korean military has announced, according to the local Yonhap news agency.
South Korea agreed to consider the defense system deployment after the North's launching of a long-range rocket February 7, an event widely seen as a cover for developing a long-range ballistic nuclear missile.
"We should strongly condemn the launch by working with the global community", said Prime Minister Abe.
Pyongyang has so far made no public comments on the issue.
The United States was monitoring the situation in close coordination with regional allies and partners, it said.
State Department spokesman John Kirby said Friday the US continues to need Chinese leadership and influence with respect to North Korea.
China, North Korea's key ally, has urged the government of President Kim Jong Un to return to worldwide talks and dismantle its nuclear program in return for economic assistance and security guarantees.
The formal decision to deploy THAAD comes two days after the United States placed sanctions on North Korean leader Kim Jong Un and 10 other officials for alleged human rights abuses.
It also criticised the decision to impose sanctions on the leader of its ally North Korea.
In January, North Korea conducted its fourth nuclear test, claiming it to be its first using a hydrogen bomb. Beijing has feared that could strengthen USA missile defense systems and weaken its own nuclear deterrent, although defense officials here said it would not make much difference to the US military. That was widely seen as a technological advance for the isolated state after several test failures. China, Russia and North Korea all say the THAAD deployment could help US radars spot missiles in their countries.
"We must firmly condemn it", he was quoted as saying by Japanese news agency Kyodo.
North Korea last test-fired a submarine-launched ballistic missile in April, calling it as a success that strengthened its ability to attack enemies with "dagger of destruction".
Abe also said the missile launch did not gravely affect Japan's national security, it added.
South Korea's military said that North Korea has achieved progress in the initial undersea ejection stage of its SLBM technology.
"My reaction is that Kim Jung-Un and his regime continues to test and work on their ballistic capability, and with every launch they are getting better, and they are working out their problems", he said at the North Atlantic Treaty Organisation summit in Warsaw.