By Kim Ghattas
BBC News, Washington
The two reporters have been held in North Korea since March
US Secretary of State Hillary Clinton has said she hopes North Korea will free two jailed American reporters.
Laura Ling and Euna Lee were imprisoned after apparently illegally entering North Korea from China in March.
The were sentenced to 12 years of hard labour for illegal border crossing and an unspecified "grave crime".
The US had so far appealed for their release on humanitarian grounds, but has now also acknowledged possible wrongdoing by the journalists.
This is the first time that Mrs Clinton has appealed for amnesty for Ms Ling and Ms Lee.
She said the two reporters had expressed "great remorse for the incident", adding that "everyone is very sorry that it happened".
The secretary of state had so far dismissed the North Korean charges against the women as baseless.
Her comments came a day after the pair admitted they had broken North Korean law and said they needed help from their government, in a telephone call to Lisa Ling, Laura's sister.
Mrs Clinton's comments also coincide with a signal from North Korea that it would release the two journalists if the US made a formal apology.
Han Park, a Korea-born professor at an American university, made the suggestion after a trip to Pyongyang.
He also said North Korea had delayed sending the two journalists to a prison labour camp and was keeping them in a guest house.
Professor Park has in the past acted as a link between North Korea and Washington, in an unofficial capacity.
When asked whether Washington had sent Professor Park to Pyongyang, Secretary Clinton said she had no comment to make.