The adviser quarterbacking Prime Minister Shinzo Abe's PR team secretly visited the Chinese port city of Dalian near North Korea for about four days in late October, diplomatic sources said Monday, fueling speculation that Tokyo has resumed delicate talks with Pyongyang.

Given that Dalian has been used in the past for secret meetings between Japan and North Korea, it is possible special adviser Isao Iijima also made contact with North Korean officials there in October.

The visit was revealed by several diplomatic sources in Beijing after senior Japanese diplomats were found to have traveled to Vietnam in late January for a possible meeting with North Korean officials.