Kenneth Bae and Matthew Todd Miller had been detained for months in the repressive state but were suddenly freed over the weekend, news agency AFP reported.
With no diplomatic relations between Washington and Pyongyang, Sweden has acted as an intermediary. Officials at the US State Department expressed their gratitude for Sweden's assistance.
"We also want to thank our international partners, especially our Protecting Power, the Government of Sweden, for their tireless efforts to help secure the freedom of Mr. Bae and Mr. Miller," a department spokeswoman said in a statement.
Bae was facing a 15 year sentence of hard labor for crimes against the state and Miller was serving a six-year sentence of hard labor.