Isao Iijima, an advisor to Japanese Prime Minister Shinzo Abe, returned Tokyo Saturday and briefed Cabinet Chief Secretary Yoshihide Suga on his unannounced visit to Democratic People's Republic of Korea (DPRK), reported local media.

Iijima said he had "frank talks" with senior DPRK officials, including Kim Yong Nam, chairman of the Presidium of the Supreme People's Assembly, and Song Il Ho, ambassador for talks to normalize relations with Japan, Japan's Kyodo News citing a government official as saying.

The aide told Pyongyang during his four-day visit about Japan's policies to resolve abduction, nuclear weapon and missile issues and said the abductions must be resolved under Abe's government, said Kyodo.

Iijima said Japan will not take any action unless the issues are settled and asked the DPRK to return all Japanese abducted, according to the report.

The advisor, who paid visits to DPRK with then Japanese Prime Minister Junichiro Koizumi in September 2002 and May 2004, made the surprise visit Tuesday, without informing the United States and South Korea that closely coordinate with Japan on DPRK-related issues.

Suga said he received a report on Iijima's visit, but had no comment on it. Local media said the top government spokesman will brief Iijima's trip to Abe later Saturday.