SEOUL, South Korea — The United States said Thursday that North Korea should immediately release a US citizen who was sentenced this week to 15 years of hard labor, setting up a potential new source of confrontation between the two countries that could aggravate tensions that are still high over North Korea’s nuclear war threats.
A State Department spokesman, Patrick Ventrell, said the Obama administration had ‘‘longstanding concerns about the lack of transparency and due process in the North Korean legal system.’’ Ventrell said the administration wanted the convicted American, Kenneth Bae, who was sentenced Tuesday on charges of committing hostile acts, to be granted ‘‘amnesty and immediate release.’’
Ventrell’s statement signaled the administration was not prepared, at least not now, to seek Bae’s release through a high-profile mission to North Korea, as it has done twice in the past when Americans were held by North Korean authorities essentially as hostages to gain concessions from the United States.
Asked at a briefing if such a mission to free Bae were an option, Ventrell said, ‘‘I’m not aware one way or another.’’ While he acknowledged such previous missions, he said, the administration was urging North Korea ‘‘to grant him amnesty and to allow for his immediate release, full stop.’’
Analysts of North Korea’s behavior said a US diplomatic mission to secure Bae’s release could easily be used by the country’s young leader, Kim Jong Un, as an example of Washington’s capitulation and an opportunity to burnish his profile as a tough anti-American strategist.
But by taking the tougher approach, the Obama administration is assuming the risk that one of its citizens will be incarcerated indefinitely.
The sentencing comes at a time of high tension between the North and the United States over the North’s nuclear program, and it was handed down the same day that joint US-South Korean military drills ended. With the end of the drills, some analysts have said, North Korea might tone down its bellicosity and shift its focus toward drawing Washington back to the negotiating table — using, among other things, Bae’s plight as bait.
‘‘The timing of the sentencing makes us think that the North is again playing its old card,’’ said Koh Yu-hwan, a North Korea specialist at Dongguk University in Seoul. ‘‘But will the Americans play the same game? If Washington sends a former president whenever North Korea holds an American captive, they say it will run out of former presidents.’’
Bae, 44, a Korean-American from Washington state who ran a tour business out of China, was arrested in the special economic zone of Rason in northeastern North Korea in November after leading a group of businessmen there from Yanji, China.
Like several other Americans detained in the North in recent years, Bae is a Christian, according to rights advocates. While North Korea’s Constitution guarantees freedom of religion, in practice it cracks down on religious activities, according to human rights groups, and is wary of all Christians who visit.
The North said Saturday that it was indicting Bae on charges that he tried to overthrow the government, a crime that called for a punishment as severe as the death penalty. But on Tuesday, its Supreme Court convicted him of ‘‘hostile acts,’’ a charge less grave than the original, the North said.
Bae is at least the sixth American detained in North Korea since 2009, and his punishment was the most severe. The others eventually were deported or released. Two were released in 2009 when former President Bill Clinton visited Pyongyang and met with Kim Jong Il, the leader at the time. Another was released when former President Jimmy Carter visited Pyongyang.
Americans recently held prisoner in the North were kept in special facilities, away from domestic inmates, possibly out of fear that when released, they would testify about the condition of prison camps where the State Department says starvation and forced labor remain rampant.