National Security Advisor Jake Sullivan spoke with his counterparts in Japan and South Korea late Monday following reports that North Korea had launched a ballistic missile that prompted Japanese officials to tell citizens to seek shelter.

The missile test over Japan was North Korea’s most significant since January. Japan hasn’t issued a shelter warning for citizens over such a matter since 2017.

Sullivan spoke with his Japanese and South Korean counterparts in which they “consulted on appropriate and robust joint and international responses,” according to a statement by the White House.

“The United States will continue its efforts to limit the DPRK’s ability to advance its prohibited ballistic missile and weapons of mass destruction programs, including with allies and UN partners,” the statement read.

Japanese Prime Minister Fumio Kishida called the launch “reckless.”

“The firing, which followed a recent series of launches by North Korea, is a reckless act and I strongly condemn it,” Kishida told reporters according to the Associated Press.

The U.S. Embassy in Tokyo responded shortly after the launch of the missile, relaying Japan’s warning of the launch.

The firing of the intermediate-range ballistic missile over Japan prompted evacuations and and suspended trains in the country. Japanese officials said they believe the weapons eventually landed in the Pacific Ocean, according to AP.

Updated 11:07 p.m.