The man illegally entered North Korea via China last month and confessed to have done so under the direction of the US Central Intelligence Agency, the North's state media said.

Pompeo thanked Wallstrom for "Sweden's role in securing the release of an American citizen from North Korea," department spokeswoman Heather Nauert said in a statement.

He also "thanked the Swedes for their support and services as our Protecting Power in North Korea, and discussed other issues of mutual concern."

Sweden serves as a liaison channel between the US and North Korea, which have yet to establish diplomatic ties.

Pompeo issued a statement Friday saying that the US "appreciates the cooperation" of North Korea and the Swedish Embassy in Pyongyang

North Korea has previously held American citizens and has been accused of using them as bargaining chips in talks with the US.

In May, the North released three Korean-American detainees ahead of a high-stakes June summit between its leader, Kim Jong-un, and US President Donald Trump.

The latest move comes as US-North Korea negotiations over the regime's nuclear weapons program have stalled.

Trump has said he still expects to have a second meeting with Kim early next year.

Their first meeting in Singapore yielded a commitment by Kim to work toward "complete" denuclearization of the Korean Peninsula in exchange for security guarantees from the US. (Yonhap)