Japan held a “secret” meeting with North Korea in Vietnam in July without informing the United States, according to media reports.

Talks were reportedly held between Shigeru Kitamura, head of Japan’s Cabinet Intelligence and Research Office, and Kim Song-hye, a senior North Korean official in charge of reunification.

Japan’s decision not to inform the US government of the meeting, which was reported in the Washington Post, was said to have caused “irritation” among senior officials.

The talks also reflect Tokyo’s growing concern that it is unable to depend on the US to lobby on its behalf in relation to key domestic issues such as the abduction of its citizens in North Korea.

US President Donald Trump told Tokyo following his historic summit with North Korean leader Kim Jong-un in June that he had raised the emotive issue during discussions.

However, a joint statement issued after the Singapore talks did not refer to human rights or abduction issues in North Korea, with Pyongyang taking the position that the matter had been settled.

Tokyo has long sought the return of at least a dozen Japanese nationals kidnapped by Pyongyang in the 1970s and 1980s in order to train its spies, with Shinzo Abe, the prime minister, making it a cornerstone of his rise to power.