(CNN) -- North Korea may consider a tougher punishment for a jailed American citizen if the United States "persists in its hostile approach" toward Pyongyang, North Korea's official news agency said Thursday.
North Korea said the United States is "persistently antagonizing" the country over the sinking of a South Korea warship in March, an act Seoul blames on North Korea, the Korean Central News Agency reported.
"Such moves have gone beyond the tolerance limit," said North Korea, which vehemently denies the charge that it fired a torpedo at the ship, the Cheonan, sinking it and killing 46 members of its crew.
The United States is ramping up international pressure against North Korea, KCNA said.
"The DPRK had already solemnly declared that it would consider the prevailing situation as a war phase and handle all relevant issues according to a wartime law," the news agency said. DPRK is an acronym for North Korea's official name, the Democratic People's Republic of Korea.
North Korea said it is examining what "additional" steps it will take against Aijalon Mahli Gomes, an American man who has been sentenced to eight years hard labor for illegally entering North Korea. He was arrested after crossing the North Korea-China border on January 25.
