"The South Korean military detected multiple projectiles suspected of being short-range ballistic missiles launched into the East Sea," South Korea's military said, referring to the body of water also known as the Sea of Japan.

The launch came a day after Japan's foreign minister Takeshi Iwaya held talks in South Korea with top officials as the Asian neighbours seek to strengthen ties before US President-elect Donald Trump returns to office.

Seoul's military said the launch took place around 09:30 am local time (0030 GMT).

It said it was maintaining "full readiness" and sharing information on the launches with the United States and Japan while "strengthening surveillance and alertness" for more launches.

Last week, Pyongyang fired what it said was a new hypersonic missile system aimed at deterring the country's rivals in the Pacific.

The location of the test site was undisclosed but images released by North Korean state media KCNA showed leader Kim Jong Un observing last week's launch with his teenage daughter Ju Ae.

Kim said the missile flew 1,500 kilometres (930 miles) -- beyond the 1,100-kilometre (680-mile) figure given by South Korea's military -- and travelled at 12 times the speed of sound before landing in the ocean.

KCNA cited the use of a "new compound of carbon fibre" in the missile's engine, which experts warned could allow Pyongyang to hit further targets with technology to which only the United States, Russia and China currently have access.

The launch also used a "new comprehensive and effective method" for its flight and guidance control system, KCNA said.

Experts said the latest launch on Tuesday could be sending a message to the incoming Trump administration.

"It could be aimed at the US," said Yang Moo-jin, president of the University of North Korean Studies in Seoul.

"It may indicate an intention put pressure ahead the Trump administration's second term."

- US warnings -

Last week's alleged hypersonic missile launch was North Korea's first since Trump won the November US election and it came as US Secretary of State Antony Blinken was visiting South Korea.

On his trip to South Korea, a fierce rival of the North, Blinken said Russia was increasing cooperation with Pyongyang, adding they were working ever more closely on advanced space technology.

Blinken also voiced renewed concern that Russia, a veto-wielding UN Security Council member, would formally accept North Korea as a nuclear state in a blow to global consensus that Pyongyang must end its programme.

In late October, North Korea test-fired what it said was its most advanced and powerful solid-fuel intercontinental ballistic missile (ICBM). Days later, it fired a salvo of short-range ballistic missiles.

In response, South Korea fired a ballistic missile into the sea in a show of force.

US and South Korean intelligence also believe that North Korea late last year sent thousands of troops to fight against Ukraine and has already suffered hundreds of casualties.

But neither North Korea nor Russia has officially confirmed that Pyongyang's forces are fighting for Moscow.