North Korea fired on early Tuesday unidentified projectiles twice from an inland area in the direction of the Sea of Japan to the east, South Korea's military said.
The launches come amid speculation that the North is working hard to develop new weapons as it has continued test-firing what appeared to be short-range ballistic missiles and other projectiles even after a U.S.-South Korea joint military exercise ended last month.
Pyongyang has denounced the Aug. 5-20 exercise as a rehearsal for an invasion and said its launches were a response to it.
Tuesday's projectiles were launched from South Pyongan Province in the central part of North Korea, at 6:53 a.m. and 7:12 a.m., flying a maximum of some 330 kilometers, according to South Korea's Joint Chiefs of Staff.
It was the eighth round of launches by the North since late July and the first since Aug. 24. The North also launched projectiles twice in May.
Japan's Defense Ministry said there was no imminent threat to Japan following the latest North Korean launches.
The ministry said in a statement that it did not confirm any ballistic missiles entering Japanese territory or its exclusive economic zone.
Defense Minister Takeshi Iwaya told reporters in Tokyo that North Korea, through its repeated launches, has been trying to advance its related technology, and that Japan will do its utmost to remain vigilant by taking the North Korean move seriously.
In Seoul, the South Korean government held a meeting of the National Security Council chaired by Chung Eui Yong, director of the National Security Office.
Council members expressed deep concerns over North Korea's repeated launches of short-range projectiles, according to the office of President Moon Jae In.
Tuesday's launches, which could have violated U.N. resolutions banning North Korea from using ballistic missile technology, came a day after Pyongyang signaled a willingness to restart stalled denuclearization negotiations with the United States.
"We have willingness to sit with the U.S. side for comprehensive discussions of the issues we have so far taken up at the time and place to be agreed late in September," North Korea's First Vice Foreign Minister Choe Son Hui said late Monday through her country's official media.
U.S. President Donald Trump has downplayed North Korea's ballistic missile launches, saying Washington and Pyongyang have a really good relationship and that North Korean leader Kim Jong Un has been "pretty straight with me."