Senior diplomats from Japan the United States and South Korea gathered Tuesday in Tokyo to discuss North Korea's missile and nuclear development a day after Pyongyang announced it successfully tested new long-range cruise missiles, suggesting advancement of its military capabilities.

The three-way meeting included U.S. Special Representative for North Korea Policy Sung Kim, South Korea's Special Representative for Korean Peninsula Peace and Security Affairs Noh Kyu-duk and Japan's Director-General for Asian and Oceanian affairs Takehiro Funakoshi.

Japanese Foreign Minister Toshimitsu Motegi told a regular news conference Tuesday that the trilateral meeting had been scheduled before North Korea’s test-firing of the missiles, but the meeting the day after would be a “good occasion to reconfirm close cooperation among the three countries and discuss the latest North Korean situation.”

Japanese officials and some experts said North Korea’s weekend missile test-firing was a “new threat” to the region.

On Monday, the state-run Korean Central News Agency reported that the missiles showed they can hit targets 1,500 kilometers (930 miles) away.

The North hailed its new missiles as a “strategic weapon of great significance,” suggesting that they were developed with the intent to arm them with nuclear warheads. North Korea says it needs nuclear weapons in order to deter what it claims is hostility from Washington and Seoul.

Japan and South Korea are separate key allies for the U.S. presence in the Asia-Pacific region.