U.S. Senator John Kerry is calling on North Korea to free on humanitarian grounds the American it has sentenced to eight years of hard labor for illegal entry.

Kerry, the chairman of the Senate Foreign Relations Committee, urged the North to make the right decision and return Aijalon Mahli Gomes to the U.S.

The North has also fined Gomes, a former English teacher in South Korea, 70 million North Korean won, or some 700-thousand U.S. dollars.

Gomes entered North Korea via the communist country’s border with China and is the fourth American to have been detained by the North in the last year.