WASHINGTON -- The United States called Saturday for the "immediate release" of Merrill Newman, an 85-year-old Californian detained in North Korea.

The Korean War veteran was plucked off a plane last month as he was leaving the reclusive state after a tourist visit.

"Given Mr Newman's advanced age and health conditions, we urge the (Democratic People's Republic of Korea) to release Mr Newman so he may return home and reunite with his family," National Security Council spokeswoman Caitlin Hayden said.

In addition to calling for Newman's "immediate release," Hayden also urged Pyongyang to free another American, Kenneth Bae.

The 45-year-old tour operator was arrested a year ago and sentenced to 15 years' hard labor on charges of seeking to topple the government.

"We continue to urge the DPRK authorities to grant him amnesty and immediate release," Hayden said.

"We remain deeply concerned about the welfare of the US citizens held in custody in the DPRK."

The State Department said the Swedish Embassy, acting on Washington's behalf since the United States has no formal ties with Pyongyang, was given "consular access" to Newman on Saturday.

Earlier, North Korea for the first time officially admitted holding Newman, saying he has been detained for "hostile acts" against the communist country.

Newman was held after entering the North "under the guise of a tourist,"

the official KCNA news agency said.

KCNA said Newman had committed crimes both as a tourist and during his participation in the Korean War six decades ago and published an apology running to nearly 600 words -- parts of it written in poor English -- in which he allegedly confessed to his crimes.

The retired financial executive has been accused of infringing upon the "dignity and sovereignty" of the secretive state and "slandering its socialist system, quite contrary to the purpose of the tour," the report said.

The American had also masterminded espionage and subversive activities during the 1950-53 Korean War and was involved in the killing of North Korean soldiers and innocent civilians, it added.

"I realize that I cannot be forgiven for my offensives but I beg for pardon on my knees by apologizing for my offensives sincerely toward the (North

Korean) government and the Korean people and I want not punish me," KCNA quoted Newman as saying.

The State Department said it had seen the KCNA report according to which Newman apologized for the "misunderstanding" that led to his detention.

However, the diplomatic agency said it had "no other information regarding the reason for his detention."

"At this time, the Department recommends against all travel by US citizens to North Korea," it said in echoing Hayden's calls for both Newman's and Bae's release.

Newman's wife Lee has said her husband of 56 years, who has heart problems, was detained on October 26 shortly before takeoff in Pyongyang. He had just completed a 10-day tour of the country, "a trip he had looked forward to making for a long while," she added. (AFP)