Japanese diplomats are visiting North Korea for the first time in 15 months. The diplomats appear to have dual assignments: take custody of a Japanese man facing drug charges and discuss the fate of the family members of former Japanese abductees.

Japan's Foreign Ministry has confirmed that four officials secretly traveled to North Korea on Tuesday. They apparently are investigating the arrest of a Japanese man in North Korea last October who is accused of attempted drug smuggling.

The Foreign Ministry says it inquired about the man at the North Korean Embassy in Beijing, but received no response until recently. Tokyo officials describe the man as a gangster.

Pyongyang's Korean Central News Agency has said the man, whom it identified as a trader, tried to bribe a North Korean to buy drugs from a third country and smuggle them into Japan on a North Korean ferry.

Japanese police have long accused North Korea of being a major source of illegal drugs sold in Japan.

Japanese media on Wednesday say the diplomats are expected to stay in Pyongyang until Saturday and are likely to discuss the fate of the relatives of

Japanese abductees. Five Japanese who were kidnapped by North Korean agents in the 1970's and 1980's returned to Japan in October 2002. But their children and the spouse of one abductee remain in North Korea.

Japanese officials say they will reveal more details about the mission after the diplomats return from Pyongyang.

Chief Cabinet Secretary Yasuo Fukuda said on Wednesday that the team will negotiate to take custody of the suspected Japanese drug smuggler. Mr. Fukuda says previously it has been difficult to contact North Korean officials to discuss matters but that is changing now.

Also on Wednesday, South Korean President Roh Moo-hyun urged patience regarding a solution to the North Korean nuclear standoff. Mr. Roh told reporters that a private U.S. delegation's visit to North Korea last week demonstrates that Pyongyang is trying to solve the problem.

The unofficial delegation visited the North's Yongybyon nuclear site, where it has operated a weapons program in violation of several international accords.

Five countries - South Korea, China, Japan, the United States and Russia - have been trying to arrange of second round of talks with North Korea about ending its nuclear ambitions. A first round, held in Beijing last August, ended inconclusively.

The South Korean president also predicted an significant improvement in relations with North Korea - but only after an end to the nuclear impasse. Mr. Roh suggested a warming of ties might include a visit to Seoul by North Korean leader Kim Jong-il.