SEOUL (Reuters) - North Korea fired two short-range missiles off its east coast on Thursday, South Korea's military said, less than an hour after Pyongyang warned of an "inevitable" response to military drills staged earlier in the day by South Korean and U.S. troops.
The latest action by North Korea came as U.S. President Joe Biden's national security adviser, Jake Sullivan, was in Tokyo for meetings with his Japanese and South Korean counterparts.
Sullivan and South Korea's Cho Tae-yong and Japan's Takeo Akiba discussed North Korea's missile programme and confirmed they would work closely together to get Pyongyang to abandon its nuclear weapons, a Japanese readout of their meeting said.
In a joint statement released by the White House, the U.S., South Korea and Japan condemned North Korea's missile launches and said they violated multiple United Nations Security Council resolutions.
Separately on Thursday, the U.S. Treasury Department said it had imposed sanctions on two China-based North Korean nationals it accused of being involved in the procurement of equipment and materials in support of the country's ballistic missile program.
A Treasury statement said North Korea continued to use a network of representatives abroad, including in China and Iran, to illicitly import components necessary for its weapons of mass destruction and ballistic missile programs.
Japan's defence ministry said the two ballistic missiles landed within its exclusive economic zone (EEZ), possibly having flown on an irregular trajectory.
They landed in the Sea of Japan about 250 km (155 miles) north-northwest of Hegura island, the 13th time North Korean missiles had landed within Japan's EEZ, Japan said.
Speaking to reporters, Japanese Prime Minister Fumio Kishida called it "an escalation of provocations against the international community as a whole" and said Japan had launched a strong protest against North Korea.
South Korean President Yoon Suk Yeol watched as several thousand South Korean and U.S. troops took part in joint live-fire exercises on Thursday, in the latest show of force that the allies say is necessary to deter North Korea.
North Korea's Ministry of National Defence said the drills were escalating military tensions in the region and its forces would sternly respond to "any kind of protests or provocations by enemies".
Pyongyang unsuccessfully tried to launch a spy satellite last month, its first satellite launch since 2016.
Diplomatic efforts to reduce tensions or persuade Pyongyang to abandon its nuclear arsenal have stalled.
South Korea sued North Korea on Wednesday for $35 million in compensation for a liaison office that North Korea blew up in 2020, in a case highlighting the breakdown of ties between the neighbours as the North presses on with its weapons programmes.