PYONGYANG - An adviser to Japanese Prime Minister Shinzo Abe arrived in the Democratic People's Republic of Korea (DPRK) Tuesday, the official KCNA news agency reported.

The report did not give more details on Isao Iijima's unannounced trip, which sparked wide international speculations.

Iijima was also a top advisor to former Prime Minister Junichiro Koizumi, who visited Pyongyang for talks with then DPRK's leader Kim Jong-il in September 2002 and May 2004.

An official from the DPRK's Foreign Ministry welcomed Iijima at Pyongyang airport, according to Japan's Kyodo News Agency.

The DPRK and Japan have no diplomatic relations. Senior officials from the two countries held talks on ties in the Mongolian capital of Ulan Bator last November.

Situation on the Korean Peninsula worsened since the DPRK conducted its third nuclear test in February, which drew great concerns and condemnation from the international community.

Japan has been cooperating with the United States and the Republic of Korea on DPRK-related issues and extended its unilateral sanctions against the DPRK for another two years last month.