North Korea drops U.S. envoy's invite to see detained American Kenneth Bae

Updated 2:55 p.m. ET

WASHINGTON North Korea has rescinded its invitation for a senior U.S. envoy to travel to Pyongyang to seek the release of a detained American, the State Department said Friday.

Bob King, the U.S. special envoy for North Korean human rights, was due to travel from Tokyo to Pyongyang on Friday to request a pardon and amnesty for Kenneth Bae and return the next day.

Bae was sentenced in April to 15 years of hard labor by the authoritarian state, accused of subversion.

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Department spokeswoman Marie Harf said the U.S. is "surprised and disappointed by North Korea's decision" and remains gravely concerned about Bae's health.

His family released a statement saying they were "disappointed" with the news and hoped North Korea and U.S. diplomats would resume talks soon. "It has been 301 days since Kenneth has been detained. With every day, we continue to pray," it read.

King's visit would have been the first public trip to North Korea by an administration official in more than two years and could have provided an opening for an improvement in relations.

U.S.-North Korean relations are already severely strained by concerns overPyongyang's nuclear program. King intends to return to Washington from Tokyo on Saturday.

"We have sought clarification from the DPRK about its decision and have made every effort so that Ambassador King's trip could continue as planned or take place at a later date," Harf said in a statement, referring to the country's formal title of the Democratic People's Republic of Korea.

"We remain gravely concerned about Mr. Bae's health and we continue to urge the DPRK authorities to grant Mr. Bae special amnesty and immediate release on humanitarian grounds."

Bae, a 45-year-old tour operator and Christian missionary, was arrested last November and accused of committing "hostile acts" against North Korea. He suffers multiple health problems and was recently hospitalized.

On Wednesday in Tokyo, King had cautioned that Washington had received no guarantees from Pyongyang that Bae would be freed.

North Korea has previously used detained Americans as bargaining chips in its standoff with the U.S. over its nuclear and missile programs. Multination aid-for-disarmament talks have been on hold since 2009, and efforts by Washington to negotiate a freeze in the North's nuclear program in exchange for food aid collapsed 18 months ago.

Bae is at least the sixth American detained in North Korea since 2009. The others were eventually allowed to leave without serving out their terms, some after prominent Americans, including former Presidents Bill Clinton and Jimmy Carter, visited North Korea.

The last one to be freed was Eddie Jun. Jun, a Korean-American from California, was arrested for alleged unauthorized missionary work during several business trips to the country. He was brought back to the U.S. when King last visited Pyongyang in May 2011.