The U.S. State Department is calling for the release of an American citizen sentenced to eight years of hard labor in North Korea for allegedly entering the country illegally earlier this year.

The North slapped the sentence --- complete with a fine of 70 million North Korean won or 700-thousand U.S. dollars --- on Aijalon Mahli Gomes on Wednesday.

In a daily briefing, State Department spokesman Philip Crowley said the U.S. hopes the North will grant Gomes amnesty and release him as soon as possible. He said Washington will work with its protecting power Sweden to make those views known to Pyongyang.

Crowley also reiterated "concerns about the lack of transparency and due process in the North Korean legal system."

Gomes came to South Korea from Boston two years ago and taught English. He's the fourth American the North has detained since early last year. It's not yet known why he went to North Korea.