SEOUL, May 21 (Yonhap) -- The U.S. ambassador in Seoul called on North Korea Tuesday to improve the "horrible" human rights situation in the totalitarian state, saying that both Seoul and Washington are deeply concerned about the welfare of the North Korean people.

"It's very heart-wrenching to see North Korean citizens," Ambassador Sung Kim told a forum on North Korea policy. "North Korean citizens are not eating well, not living well and not receiving medical treatment because their government has chosen to be irresponsible."

   "It is very unfortunate that North Korean citizens are not given the opportunity" to live a decent life "because of the horrible, horrible human rights situation in North Korea."

   North Korea has long been labeled one of the worst human rights violators in the world. The regime does not tolerate dissent, holds hundreds of thousands of people in political prison camps and keeps a tight control over outside information.