U.S. envoy for North Korea: reactor restart serious matter, if true

TOKYO (Reuters) - The U.S. special envoy for North Korea said on Thursday the reported restart of a research reactor at North Korea's Yongbyon nuclear complex would be a serious matter if true.

A U.S. research institute and a U.S. official said on Wednesday satellite imagery suggested North Korea had restarted a research reactor capable of producing plutonium for weapons.

"These reports, I believe, are unconfirmed. What I can't do is comment on intelligence matters ... If it turns out these reports are true ... it would be a very serious matter ... It would violate a series of U.N. Security Council resolutions," Special Representative for North Korea Policy Glyn Davies told reporters in Tokyo.

(Reporting by Kiyoshi Takenaka; Editing by Rbert Birsel)