South Korea's and Japan's militaries say North Korea has again test-fired a ballistic missile, which flew an estimated 40 minutes before landing in the Sea of Japan. It is the 12th provocation of the year, breaking United Nations resolutions barring such tests.
The move by Pyongyang comes following a White House summit between President Trump and South Korean President Moon Jae-in, in which the two countries pledged to coordinate on North Korea policy and continue a security alliance that has lasted more than 60 years.
South Korean president Moon Jae-in assembled the country's national security team for an emergency meeting.
Trump responded to the test in tweets. Earlier he had indicated the reliance on China to help curb Pyongyang "hasn't worked out," and in two successive tweets following the morning missile launch, Trump seemed to poke fun at the North Korean leader, Kim Jong Un. The tweets read:
"North Korea has just launched another missile. Does this guy have anything better to do with his life? Hard to believe that South Korea.....and Japan will put up with this much longer. Perhaps China will put a heavy move on North Korea and end this nonsense once and for all!"
China, for its part, says it has already increased the presence of security agents on its border with North Korea, signed on to U.N. sanctions packages and more strongly enforce sanctions that bar imports of North Korean coal into China. Coal accounts for an estimated 30 percent of North Korea's exports.
Jihye Lee contributed to this post.