TOKYO -- Japanese Prime Minister Shinzo Abe held a telephone conference with U.S. President Donald Trump on Tuesday morning. Both men agreed that the launch of ballistic missiles by North Korea on Monday was "a clear threat to the international community" and that the threat posed by Pyongyang has entered "a new phase."

The two leaders spoke for approximately 25 minutes, and agreed that Japan, the U.S. and South Korea will work together on the matter, and the three will look to call on China to cooperate due to its its leverage over North Korea.

Japanese Prime Minister Shinzo Abe speaks with reporters at his office in Tokyo on Mar. 7.

According to Japanese officials, Abe told Trump that Japan is ready to assume a "large role and responsibility to enhance the deterrence provided by the Japan-U.S. alliance," and will move swiftly to do so. It was also agreed that the foreign and defense ministers of the two countries should hold "two-plus-two" security talks in the near future.

Trump told Abe that the U.S. stands by Japan "100%," and the U.S.'s commitment to Japan's national security remains unchanged.

Abe also commented to reporters that being able to have the conversation all but immediately after the launch was "testament to the fact that Japan and the U.S. stood side by side." He added: "With the backing of the strong U.S. military commitment, we will look to deter North Korea from further provocation and strongly urge it to comply with the United Nations Security Council Resolution."

The missiles were fired from an area near Tongchang-ri in the country's northwest early Monday morning. Four missiles flew some 1,000 kilometers eastward before falling into the Sea of Japan some 300km to 350km east of Akita Prefecture, according to the Japanese Defense Ministry.

State-broadcaster Korean Central News Agency reported on Tuesday morning that the missile launch was a drill aimed at U.S. troops stationed in Japan and called it "a success." It is rare for Pyongyang to openly claim that Japan-based U.S. forces were the target.

Abe related to Trump how the launch had been described and said that "this was a clear act of provocation to Japan, the U.S., the region and the international security and cannot be accepted." He also denounced the fact that three missiles fell within Japan's exclusive economic zone.

Japan's Defence Minister Tomomi Inada and her U.S. counterpart James Mattis also held phone conversations on Tuesday. They agreed not to accept the launch and that this was an irresponsible act that threatened the stability of the region. Mattis said that the U.S. remained undeterred in its extended deterrence, including the nuclear umbrella.

Fumio Kishida, the Japanese foreign minister, told a press conference after a cabinet meeting that Japan, the U.S. and South Korea had "requested the U.K., the current president of the UN Security Council, to call an emergency meeting."