Pyongyang, North Korea - North Korea carried out another missile test on Thursday hours after a visit by US Vice President Kamala Harris to South Korea.

Pyongyang's rocket was the third within the space of a week. It came shortly after Harris and President Yoon Suk Yeol condemned an earlier launch by the North.

Pyongyang's latest missile was fired towards the Sea of Japan – known in Korean as the East Sea – Yonhap news agency reported, as were the earlier rockets. UN resolutions prohibit North Korea from testing any kind of ballistic missile.

Harris had slammed a rocket launch by Pyongyang a day before she visited Seoul, amid heightened tensions in the region as the North has carried out a series of nuclear-capable missile tests this year.

The US and South Korea have long feared North Korea could conduct a new nuclear test at any time. The isolated nation is subject to tough international sanctions because of its nuclear weapons program.

Negotiations between the US and North Korea have not progressed since a failed summit meeting between the two countries in Vietnam in February 2019.

During the visit, Yoon and Harris also discussed China and Taiwan and "the effort to preserve peace and stability across the Taiwan Strait," according to a White House statement.

Taiwan has had an independent government since 1949, but China considers the democratic island part of its territory and opposes any form of official contacts between Taiwan and other countries.

Beijing has responded angrily to visits by officials from the US in recent weeks, including starting large-scale military maneuvers around Taiwan.

After Thursday's talks in Seoul that lasted nearly one-and-a-half-hours, Harris visited the heavily fortified border between South and North Korea, where she met several US soldiers and their family members.

She had previously been in Japan to attend ceremonies for the assassinated former prime minister, Shinzo Abe, on Tuesday.