The foreign-funded university that two of the three released American detainees taught at has welcomed the trio's release.
The Pyongyang University of Science and Technology (PUST) was founded by evangelical Christians from overseas and opened in 2010.
It has 560 students and 100 "international volunteers", according to its website.
Agricultural expert Kim Hak-song and former accounting professor Tony Kim were both lecturers at the institution but were arrested by North Korean authorities as they were leaving the country.
The university previously said their detentions were "not connected in any way with the work of PUST", and sources stress that it carries out no Christian proselytisation, which is unwelcome in the North.
But it is understood the duo may have come to the attention of the Pyongyang authorities through previous Christian activities elsewhere.
The three detainees were granted "amnesty" by Pyongyang following a meeting between Secretary of State Mike Pompeo and North Korean leader Kim Jong Un, and landed back in the United States on Thursday, to be welcomed by President Donald Trump.
"Our hopes and prayers have been fulfilled by their release," PUST said in a statement.
The university expressed "sincere hope" that the detainees would be able to "now enjoy some peace and rest with their families and friends, and begin to rebuild normal life".
The captivity of the US citizens has brought renewed attention to the school, known to provide foreign education to many children of the country's elite.
On its website, PUST says its mission is "to pursue excellence in education, with an international outlook, so that its students are diligent in studies, innovative in research and upright in character, bringing illumination to the Korean people and the world".
Korean American writer Suki Kim went to PUST undercover as an English teacher in 2011 and later wrote a book about her experiences.
"PUST offers a mutually beneficial arrangement for both North Korea and the evangelicals," she wrote in an essay published in the Washington Post last year following Tony Kim's detention.
"The regime gets free education for its youth and a modern facility... while the evangelicals get a footing in the remote nation," she said.
Although religious freedom is enshrined in the North Korean constitution, it does not exist in practice and religious activity is severely restricted to officially-recognised groups linked to the government.