The U.S. government is again calling for the release of a U.S. citizen sentenced to eight years of hard labor in North Korea.
State Department spokesman Mark Toner said Thursday Pyongyang should not link the case to political issues between U.S. and North Korean governments.
Toner spoke in response to North Korea's threat that it is considering harsher punishment for Aijalon Mahli Gomes, who was sentenced to prison and fined about $700,000 on charges of entering the country illegally in January.
The official Korean Central News Agency reported Thursday that U.S. calls for Gomes' release will not be considered because of Washington's actions following the March 26 sinking of a South Korean warship, which killed 46 sailors.
An international investigation concluded that the South Korean frigate Cheonan was attacked by a North Korean torpedo.
Pyongyang rejected the claim as a "fabrication" and threatened war if international sanctions were imposed.
Gomes, a former English teacher in South Korea, is the fourth American citizen to be held in North Korea in the past year. Three have been released.
Also Thursday, North Korea demanded nearly $65 trillion from the United States to compensate for six decades of alleged hostilities against the communist country. The North Korean news agency said the figure would include compensation for civilian casualties.
This year marks the 60th anniversary of the start of the Korean War.
