North Korea test-fired a ballistic missile on Saturday, South Korea's and U.S. militaries said, defying intense pressure from the United States and the reclusive state's main ally, China.
U.S. and South Korean officials said the test, from an area north of the North Korean capital, Pyongyang, appeared to have failed, in what would be a fourth successive unsuccessful missile test since March.
The test came as U.S. Secretary of State Rex Tillerson warned the U.N. Security Council that failure to curb North Korea's nuclear and ballistic missile programmes could lead to "catastrophic consequences".
U.S. officials, speaking on condition of anonymity, said the missile was probably a medium-range weapon known as a KN-17 and appears to have broken up within minutes of taking off.
South Korea's military said the missile, fired from the Pukchang region in a northeasterly direction, reached an altitude of 71 km (44 miles) before disintegrating a few minutes into flight.
The North has been conducting missile and nuclear weapons related activities at an unprecedented rate since the beginning of the year and is believed to have made some progress in developing intermediate-range and submarine-launched missiles.
Tension had spiked on the Korean peninsula over concern the North may conduct a long-range missile test, or its sixth nuclear test, around the time of the April 15 anniversary of its state founder's birth, or the day marking the founding of its military this week.
The timing of the launch suggested it was calculated to send a message as North Korea remained under the scrutiny of world powers, said Kim Dong-yub, an expert at Kyungnam University's Institute of Far Eastern Studies in Seoul.
“It was planned at a complicated timing around the end of the South Korea-U.S. joint military drills, the United States talking about military options and the announcement of North Korea policies and the Security Council meeting,” Kim said.
South Korean and U.S. forces have been conducting annual military drills since the beginning of March that conclude at the end of April.
Kim said North Korea might have obtained the data it wanted with the missile's short flight, then blown it up in the air.
U.S. President Donald Trump told Reuters in an interview on Thursday North Korea was his biggest global challenge and a "major, major conflict" with it was possible over its nuclear and ballistic missile programmes.
Trump said and he praised Chinese leader Xi Jinping for "trying very hard" to rein it in.
"North Korea disrespected the wishes of China & its highly respected President when it launched, though unsuccessfully, a missile today. Bad!," Trump said in a post on Twitter after the launch.
In a show of force, the United States is sending the USS Carl Vinson aircraft carrier group to waters off the Korean peninsula, where it will join the USS Michigan, a nuclear submarine that docked in South Korea on Tuesday.
The Trump administration could respond to the latest missile test by speeding up its plans for new U.S. sanctions, including possible measures against specific North Korean and Chinese entities, a U.S. official told Reuters.
"Something that's ready to go could be taken from the larger package and expedited," said the official, who declined to be identified.
The launch could also give Trump leverage to press the Chinese to do more to rein in the North, the official added.
Earlier, both China and Russia rebuked a U.S. threat of military force at a meeting of the U.N. Security Council on North Korea.
Chinese Foreign Minister Wang Yi told the 15-member council it was not only up to China to solve the North Korean problem.
"The key to solving the nuclear issue on the peninsula does not lie in the hands of the Chinese side," Wang told the council in blunt remarks that Tillerson later rebuffed.
The U.N. Security Council is likely to start discussing a statement to condemn the missile launch, said diplomats, adding that it was unlikely to be issued on Friday. The Security Council traditionally condemns all missile launches by Pyongyang.
Such routine condemnation and a series of sanctions resolutions since 2006, when North Korea conducted its first nuclear test, have done little to impede its push for ballistic missiles and nuclear arms.
"It could have happened today exactly because we had the meeting," Italian U.N. Ambassador Sebastiano Cardi, chair of the Security Council's North Korean sanctions committee, told reporters when hearing of the test. "It's illegal, it should not be done, it's another provocative action by North Korea.”
Japan condemned the launch as absolutely unacceptable and a violation of U.N. resolutions. There was no immediate reaction from China.
(Additional reporting by Ju-min Park in Seoul, Idrees Ali in Washington, Malcolm Foster in Tokyo and Lesley Wroughton at the United Nations; Editing Lincoln Feast, Robert Birsel)