TOKYO -- A political aide to the prime minister of Japan made a sudden, rare visit to North Korea on Tuesday. Japanese officials refused to say what he was doing there.
Japan and North Korea do not have formal diplomatic ties. Talks between the two governments, which resumed last August after a four-year hiatus, were broken off again in December after North Korea tested a rocket.
Kyodo News, a Japanese news agency, reported that the adviser, Isao Iijima, was met at the airport at Pyongyang, the capital, by a North Korean official identified as Kim Chol-ho, a vice director in the Foreign Ministry. Such a reception would suggest that Mr. Iijima, who is a senior adviser to Prime Minister Shinzo Abe, was there on official business.
However, officials in Mr. Abe's office refused even to confirm that Mr. Iijima had gone to Pyongyang, let alone give a reason.
Both Kyodo and N.H.K., Japan's national television broadcaster, carried images from North Korean television showing Mr. Iijima arriving at the airport and being greeted by a group of North Koreans.
Japan has taken a hard line against North Korea, largely because of public anger here over the abduction of at least a dozen Japanese citizens in the 1970s and 1980s; they were taken to North Korea to teach languages to spies. Mr. Abe rose to national prominence a decade ago by taking up the cause of the victims, five of whom were returned to Japan by North Korea in 2002.
Mr. Iijima played a role in their return, visiting Pyongyang twice as an adviser to Junichiro Koizumi, the Japanese prime minister at the time. Mr. Koizumi secured their release when he met with the North Korean leader, Kim Jong-il, in Pyongyang in September 2002. Mr. Kim died and was succeeded by his son Kim Jong-un in 2011.
Commentators in the Japanese media speculated that Mr. Iijima may be seeking information on other Japanese citizens believed to be in the North, or may be preparing for Mr. Abe to follow Mr. Koizumi, his political benefactor, by making his own visit to Pyongyang.
This article originally appeared in The New York Times.