Seoul's military said it had "detected several projectiles presumed to be short-range ballistic missiles," the Joint Chiefs of Staff said.

The missiles were "fired from the Wonsan area of North Korea into the East Sea at around 08:10 today," they added, referring to the body of water also known as the Sea of Japan.

The launch, the nuclear-armed North's first missile test since March, came about a week after Kim oversaw the test-firing of a new warship weapons system.

Pyongyang unveiled the 5,000-ton destroyer-class vessel named Choe Hyon last month.

North Korea claims the vessel was equipped with the "most powerful weapons", and that it would "enter into operation early next year".

Some analysts have said the ship could be equipped with short-range tactical nuclear missiles -- although North Korea has not proven it has the ability to miniaturise its nukes.

The South Korean military has said the destroyer could have been developed with Russian help -- possibly in exchange for Pyongyang deploying thousands of troops to help Moscow fight Kyiv.

Russia and North Korea also recently announced that they had started building the first road bridge linking the two neighbours.

North Korea launched a flurry of ballistic missiles last year in violation of UN sanctions.

Experts have long warned that the nuclear-armed North may be testing weapons for export to Russia for use against Ukraine.

Japan's defence ministry said there was no impact on Japan from the North Korean missile, according to public broadcaster NHK.

- Testing, testing -

South Korea's military said in early March that the North fired "multiple unidentified ballistic missiles", the same day Seoul and Washington began a major annual joint military drill known as Freedom Shield.

Pyongyang also carried out a test-launch of strategic cruise missiles in the Yellow Sea in late February, which it said showed off "counterattack capabilities".

Washington -- Seoul's key security ally -- has in recent years ramped up joint military exercises and increased the presence of strategic US assets, such as an aircraft carrier and a nuclear-powered submarine, in the region to deter the North.

Pyongyang has repeatedly declared itself an "irreversible" nuclear weapons state and routinely denounces joint US-South Korea drills as rehearsals for invasion.

The two Koreas are technically still at war as the 1950-1953 conflict ended in an armistice rather than a peace treaty.

With relations souring, the North last year blew up roads and railways connecting it to the South and fortified areas of the border with more mines.

In early April, South Korea's military said its troops fired warning shots when around 10 North Korean soldiers briefly crossed the heavily fortified border that divides the peninsula.