Secretary of State Hillary Rodham Clinton has called the charges “baseless.”

The United States government had demanded that the North forgo the legal proceedings and release the two women.

Image Euna Lee, top, and Laura Ling. Credit... Yonhap/Associated Press

The sentencing came amid rising tensions between Washington and Pyongyang. Earlier Monday, North Korea threatened to retaliate with “extreme” measures if the United Nations punished it for its nuclear test last month, and Washington warned that it might try to put the North back on its list of states that sponsor terrorism, a designation that could subject the impoverished state to more financial sanctions.

“Our response would be to consider sanctions against us as a declaration of war and answer it with extreme hard-line measures,” the North Korea’s state-run newspaper, Rodong Sinmun, said in a commentary.

Ms. Ling and Ms. Lee were on a reporting assignment from Current TV, a San Francisco-based media company co-founded by Al Gore, the former vice president, when they were detained by the soldiers. The reporters were working on a report about North Korean refugees  women and children  who had fled their homeland in hopes of finding food in China.

The circumstances surrounding their capture remain unclear.

Analysts said they were a pawn in a rapidly deteriorating confrontation between the United States and North Korea  a potential bargaining chip for the Pyongyang regime and a handicap for Washington in its efforts to pressure the government over its recent missile and nuclear tests.