SEOUL, South Korea: As the U.S. The military warned the North that nuclear weapons would lead to regime change if they were used, North Korea launched two short-range ballistic missiles towards the sea on Friday, its first launch in two weeks.

The South Korean military detected both launches from North Korea's eastern coastal region of Tongchon on Friday afternoon, the Joint Chiefs of Staff in Seoul said in a statement.

The statement said South Korea strongly condemns the launches, calling them "a grave provocation" that undermines regional peace and violates U.N. Security Council resolutions banning any ballistic activities by North Korea.

The U.S. The Indo-Pacific Command said the launches highlighted the "destabilizing impact" of North Korea's illicit nuclear weapons and ballistic missile programs. The Japanese Defense Ministry said it also detected the launches and that the type of missiles used and their flight information were still being analyzed.

South Korea's Foreign Ministry said its top nuclear envoy held separate phone talks with his U.S. and Japanese counterparts soon after the launches.

It said the three agreed to strengthen trilateral coordination on North Korea while repeating their calls for the North to stop weapons tests and return to talks.

The back-to-back launches, the North's first ballistic missile tests since Oct. 14, came on the final day of South Korea's annual 12-day "Hoguk" field exercises, which also involved an unspecified number of U.S. troops this year. Next week, South Korean and U.S. air forces plan to conduct large-scale training as well.

North Korea sees such regular drills by Seoul and Washington as practice for launching an attack on the North, although the allies say their exercises are defensive in nature.

Next week's "Vigilante Storm" aerial drills, which will run from Monday to Friday, will involve about 140 South Korean warplanes and about 100 US aircraft.

Since late September, North Korea has launched a barrage of missiles towards the sea in what it called simulated tests of tactical nuclear weapons systems designed to attack South Korean and U.S. targets.

Tongchon, the launch site for the North's Friday launches, is about 60 kilometres (37 miles) away from the inter-Korean land border. The area was closer to South Korean territory than any other missile launch site North Korea has used so far this year, according to South Korea's Defense Ministry.

South Korea and the United States have strongly warned North Korea against using its nuclear weapons preemptively.

There are concerns that the North could up the ante in the coming weeks by conducting its first nuclear test since 2017.

In recent days, North Korea has also fired hundreds of shells in inter-Korean maritime buffer zones that the two Koreas established in 2018 to reduce frontline military tensions. North Korea has said the artillery firings were in reaction to South Korean live-fire exercises at land border areas.

On Monday, the rival Koreas exchanged warning shots along their disputed western sea boundary, a scene of past bloodshed and naval battles, as they accused each other of violating the boundary.