Jeffrey Fowle, imprisoned in North Korea for six months, has been released, the White House said on Tuesday, according to the New York Times.

Fowle, 56, an Ohio municipal worker, entered North Korea in April on a tourist visa. A month later, the State Department warned Americans not to travel to North Korea because of detention risk, reports NPR.

Fowle was arrested for leaving a Bible in his hotel room. Since North Korea considers religion a threat to its authoritarian government, proselytizing the Christian faith is a serious crime. The regime claimed he had violated North Korean law, contrary to his presence as a tourist.

North Korean authorities allowed American news organizations to interview Fowle in Sept. Fowle told reporters he had been granted contact with his wife and three young children who reside in Miamisburg, Ohio, but three weeks had passed since he last spoke to his family.

Previously, his family issued a public apology to North Korea if his actions committed any offense.

White House press secretary Josh Earnest told the New York Times the Pentagon arranged Fowle's flight home.

"While this is a positive decision by the DPRK, we remain focused on the continued detention of Kenneth Bae and Matthew Miller and call on the DPRK to immediately release them," Earnest told NPR, alluding to the Democratic People's Republic of Korea.

A State Department spokeswoman, Marie Harf, said officials are working hard to negotiate the release of the two remaining American prisoners in North Korea.

Miller, 24, who went to North Korea as a tourist in April and allegedly demanded asylum, was sentenced to six years' hard labor in September for committing "hostile" acts against the Pyongyang.

Bae, 45, a Korean-American businessman and missionary, was arrested in 2012 and subsequently sentenced to 15 years' hard labor because the country says he tried to overthrow the regime.