Bae made the appeal during a news conference he said was held at his request in Pyongyang, the British publication the Independent reported.
Bae was arrested in November 2012 while leading a tour group in the country. North Korea's Supreme Court said he was using his business to form groups that were trying to overthrow the government.
Bae was sentenced to 15 years of hard labor. His family has suggested he was being held because he is a Christian.
Officials transferred Bae from a labor camp to a hospital last summer because of his poor health. His family said Bae has diabetes, an enlarged heart, and a back injury that keeps him for standing for more than a half hour at one time.
During the news conference, Bae, who was born in South Korea, expressed hope that the U.S. government will do its best to secure his release.
His plea came after his sister, Terri Cheung, accused former NBA basketball player Dennis Rodman of jeopardizing her brother's release by comments intimating Bae may have done something to warrant the harsh sentence. Rodman, who went to North Korea with other former NBA players for an exhibition game against North Korean all-stars, said he would not discuss Bae's situation with North Korean leader Kim Jong Un, whom Rodman has called his friend.
The exhibition game was played on Kim's birthday.
Rodman later apologized, blaming the comments about Bae and their implication on alcohol and stress. He checked into a rehab center upon returning to the United States.