South Korea’s military said several short-range missiles flew about 300 km (186 miles) after being fired between 7:44 a.m. and 8:22 a.m (2244 to 2322 GMT Monday) from Pyongyang, the North’s capital, landing off the east coast.

It condemned the launches as a “clear provocation” and said it was sharing information on them with the United States and Japan.

The U.S. State Department also condemned the launches, saying they violated several U.N. Security Council resolutions as well as posing a threat to the region.

Japan’s defence ministry said three missiles were launched and travelled about 350 km, with a maximum altitude of 50 km.

Japanese Prime Minister Fumio Kishida condemned the launches after his country’s coast guard also reported the firing of what it said appeared to be a ballistic missile and specified that it had already ended its flight.

“North Korea’s series of actions threaten the peace and security of our region and the international community, and are absolutely unacceptable,” Kishida said, calling the launch a violation of U.N. resolutions.

South Korea’s defence minister, Shin Won-sik, said the North has been testing a new type of short-range missiles in recent weeks, and Seoul and Washington are monitoring whether those weapons were meant to be sent to Russia.

“It is unclear whether the missiles are for frontline reinforcement or exports to Russia,” he told a news conference. “But there is a significant possibility that they were making final performance checks before exporting them to Russia.”

Shin said North Korea has shipped at least 7,000 containers of mostly munitions to Russia since July to support its war against Ukraine. He had put the number at around 6,700 in late February.

The North has received fuel and food supplies in return, which appear to have temporarily eased shortages and other economic difficulties since late last year, Shin added.

North Korea’s military has been conducting exercises using conventional weapons in recent weeks, often personally overseen by the isolated state’s leader, Kim Jong Un.

The show of force by Pyongyang comes just after the militaries of South Korea and the United States finished 10 days of large-scale annual joint military drills last Thursday.

On Sunday, the South Korean military also mobilised marines, attack helicopters and amphibious assault vehicles in drills aimed at surging troop numbers to reinforce western islands near the sea border with North Korea. The North shelled the islands in 2010.

Blinken is among senior officials from around the world attending the Summit for Democracy conference, which opens on Monday. He will also meet his South Korean counterpart, Foreign Minister Cho Tae-yul.

The summit is an initiative of U.S. President Joe Biden aimed at discussing ways to stop democratic backsliding and erosion of rights and freedoms worldwide.

In its last ballistic launch on Jan. 14, North Korea fired what it said was an intermediate range hypersonic missile using solid fuel to test new booster engines and a manoeuvrable warhead.

A month later, it launched multiple cruise missiles off its east coast, including what it said was a new anti-ship missile.

(Reporting by Joyce Lee, Jack Kim and Hyonhee Shin in Seoul and Mariko Katsumura and Kaori Kaneko in Tokyo; Writing by Jack Kim; Editing by Kim Coghill, Ed Davies and Gerry Doyle and Miral Fahmy)