SOUTH KOREA- North Korea has threatened to increase punishment for an American who was sentenced to hard labor for illegally entering the country. The North's official Korean Central News Agency reported Thursday that North Korea is examining what harsher measures it would take against Aijalon Mahli Gomes in line with a wartime law. Gomes, from Boston, was sentenced in April to eight years of hard labor and fined $700,000 for entering the country illegally and for an unspecified "hostile act." KCNA said the North would be compelled to consider applying a wartime law to his case if the US persisted "in its hostile approach" to the North. Tensions have been high after a S. Korean warship sank in March and N. Korea was blamed.