The United States on Thursday (May 2) urged North Korea to grant amnesty to Kenneth Bae, a U.S. citizen sentenced to 15 years hard labor for what Pyongyang said were crimes against the state, a U.S. State Department spokesman said.

"There is no greater priority for us than the welfare and safety of U.S. citizens abroad and we urge the DPRK authorities to grant Mr. Bae amnesty and immediate release."

"There hasn't been any transparency in the case so while some of the facts are limited, to our knowledge we don't know all the facts, we are concerned that, broadly speaking, about the transparency and due process in North Korea and we think he should be released."