President Donald Trump affirmed on Tuesday America's "ironclad commitment" to Japan and South Korea's security following the latest missile test by North Korea.
Trump spoke over phone separately with the Japanese Prime Minister Shinzo Abe and South Korean acting President Hwang Kyo-Ahn, the White House said.
During the phone calls, Trump emphasised the United States' ironclad commitment to stand with Japan and South Korea in the face of the serious threat posed by North Korea.
"He emphasised that his administration is taking steps to further enhance our ability to deter and defend against North Korea's ballistic missiles using the full range of United States military capabilities," the White House said.
"Trump agreed with Prime Minister Abe and acting President Hwang to continue close bilateral and trilateral cooperation to demonstrate to North Korea that there are very dire consequences for its provocative and threatening actions," the White House said.
Meanwhile, the US Forces in Korea announced that Terminal High-Altitude Area Defence (THAAD) missile has arrived in Korean Peninsula.
Pentagon spokesperson Captain Jeff Davis said Defence Secretary Jim Mattis spoke with his Japanese counterpart Tomomi Inada to discuss North Korea's missile launches.
"Mattis and Inada both agreed that these launches are an unacceptable and irresponsible act that undermines security and stability in the region," Davis said. Mattis reaffirmed that the US remains steadfast in its defense commitments to Japan including its extended deterrence commitment, he said.
"Both Mattis and Inada agreed to cooperate closely along with the Republic of Korea to strengthen deterrence and to maintain the peace and security of Northeast Asia," Davis said. North Korea on Monday fired four ballistic missiles east of the peninsula, with Japan saying three of them landed in its waters.