Two previous attempts to launch a military surveillance satellite into space this year failed, but North Korea now asserts that the mission was a success.
It follows a September meeting between Kim Jong Un and Russian President Vladimir Putin, during which Moscow extended assistance to Pyongyang regarding its space programme.
South Korea states that it has not yet verified whether or not the satellite is operational. However, it asserts that it believes Russia assisted the North.
Subsequent to the launch, South Korea declared its intention to reinstate border surveillance along its northern frontier, thus implementing measures to halt portions of a 2018 bilateral agreement between the two nations with the objective of reducing military tensions.
The satellite, designated Malligyong-1, "accurately" entered orbit, according to the North Korean state news agency KCNA, and leader Kim Jong Un reportedly witnessed the launch.
The United Nations, which maintains sanctions against North Korea for the development of nuclear missiles, as well as the United States and Japan, among others, have condemned the launch. He reaffirmed his demand that the North resume its denuclearization efforts.
The White House characterised the action as a flagrant transgression of United Nations resolutions, and Fumio Kishida, the prime minister of Japan, condemned the launch.
The rocket passed over the Okinawa prefecture of Japan before continuing its journey towards the Pacific Ocean.
The launch was condemned "in the harshest terms" by Mr. Kishida, who added that a complaint had been filed with North Korea.
The launch occurred prior to schedule, surpassing the nine-day window that Japan had been duly informed of by Pyongyang. This was scheduled to begin on Wednesday and conclude on November 30 at 23:59 local time (14:59 GMT).
The verification of North Korea's assertion regarding the effective launch of the spy satellite remains pending. Should the rocket's identity as a surveillance satellite be verified, it would represent the North's third endeavour to deploy one this year.
Japan had previously stated that it would collaborate with South Korea and the United States to "strongly urge" North Korea to abandon the launch, which they claimed would violate United Nations resolutions.
The Japan Coast Guard stated that three maritime zones were designated in Pyongyang's notification as potential locations for satellite-carrying rocket debris to land. Two are located west of the Korean Peninsula, while the other is east of Luzon, an island in the Philippines.
The chief director of operations for the South Korean Joint Chiefs of Staff, Kang Ho-pil, issued the warning that "necessary measures" would be taken in Seoul if the launch went ahead.
Kim Jong Un, the leader of North Korea, highly values a surveillance satellite because it would enable him to more precisely forecast and plan his own counteroffensives in progress.
In contrast, Pyongyang's satellite launches have been prohibited by the United Nations Security Council on the grounds that they serve as a pretence to demonstrate the North's missile technology.
Retrieving debris from the initial North Korean launch in May, South Korea declared that the satellite had "no military utility." Following the failure of its second attempt in August, the space agency of Pyongyang planned to make another attempt in October but failed to do so.
South Korea announced its intention to deploy its own reconnaissance satellite by the conclusion of November earlier this month.
Launching the satellite will be a rocket manufactured by the American firm SpaceX. According to reports, Seoul intends to deploy five additional spy satellites into space by the year 2025.
