SEOUL — A U.S. missionary imprisoned in North Korea since 2012 has said he feels abandoned by his government and has appealed again for help in securing his release, a pro-North Korea newspaper reported on Thursday.

Kenneth Bae, who is of Korean descent, was arrested in November 2012, convicted and sentenced to 15 years hard labor last year.

"Bae said he had heard that the U.S. government is doing everything it can for his release but feels disappointment that there has been no sign of resolution when he is approaching two years in his stay in (the North) and that he feels abandoned by the U.S. government," the Choson Sinbo newspaper said.

Bae said he was suffering from illness of the spleen as well as liver, prostate and spinal problems and he asked the United States to send a special envoy to try to secure his release, said the newspaper which is published in Japan but supports the North and reflects its views.

But he indicated the envoy would have to be someone other than Robert King, U.S. envoy on North Korea human rights who the North has blocked from visiting.

"I request that the U.S. government soon dispatch a special envoy that the government ... can accept so that my problem can be resolved," Bae told the newspaper in an interview.

North Korea cancelled a visit by King in August last year and again in February this year. It is believed the North does not consider him to be senior enough.

The North views the United States as an enemy but also wants to engage with it on equal terms. They have no diplomatic relations.

North Korea has said it would not use U.S. citizens as bargaining chips.

Bae has acknowledged being a missionary and has said he conducted religious services in the North, one of the world's most isolated states and long hostile to Westerners advocating religious causes.

The United States has asked North Korea to pardon and release Bae so he can seek medical care.

The United States has also called on North Korea to release on humanitarian grounds two other Americans being held there. North Korean media has said the two, Jeffrey Fowle and Matthew Miller, would be put on trial for crimes against the state.