SEOUL: North Korea fired four short-range ballistic missiles into the western sea on Saturday, South Korea's military said, as Seoul and Washington ended a high-profile six-day military exercise.

North Korea has launched a series of missiles this week, including a possible failed intercontinental ballistic missile, drawing condemnation from the United States, South Korea and Japan, and raising speculation it could be preparing to resume nuclear weapons testing for the first time since 2017.

Saturday's launches between 11:31 and 11:59 a.m. (0231-0259 GMT) come as the United States and South Korea finished the "Vigilant Storm" exercise they began on Monday.

The missiles flew about 130 km (80 miles), reaching an altitude of about 20 km (10 miles), Seoul said.

The allied exercise involved some 240 military aircraft and two U.S. B-1B strategic bombers, as well as four F-16 and four F-35A fighters, according to South Korea's Joint Chiefs of Staff.

This is the first time the B-1B has been deployed in U.S.-South Korean drills since 2017, showing "the combined defence capabilities and determination of the Republic of Korea and the U.S. to resolutely respond to any provocations from North Korea, and the will of the U.S. to implement a strong commitment to extended deterrence," the joint chiefs said in a statement.

Pyongyang on Friday demanded the United States and South Korea halt "provocative" air exercises. South Korea said it scrambled warplanes in response to 180 North Korean military flights near the countries' shared border on Friday.

On Wednesday, North Korea fired a daily record 23 missiles, with one landing off the coast of South Korea for the first time, after Pyongyang threatened to take powerful measures unless Washington halts allied air exercises with South Korea.

As the tit-for-that exchange continued through the week, Washington called for a public United Nations Security Council meeting on Friday, where it accused Russia and China of providing "blanket protection" to North Korea from further Security Council action.

A North Korean foreign ministry spokesman issued a statement late on Friday warning that "sustained provocation is bound to be followed by sustained counteraction," said state media KCNA.

In recent years the Security Council has been split on how to deal with North Korea. In May China and Russia vetoed a U.S. attempt to impose more U.N. sanctions in response to North Korean missile launches.