Kenneth Bae has been speaking about his time in a gulag, telling CNN he would work ten hours-per-day farming, shovelling coal and carrying rocks.
From neighbouring China, he had organised 18 excursions into the authoritarian state over a six-year period before being caught with a computer hard drive containing prayers and accused of trying to overthrow the government.
After serving 735 days of a 15-year hard labour sentence and following pressure from US President Barack Obama, Mr Bae was freed in 2014.
Mr Bae told the US-broadcaster NBC: "I found my way adjusting to life in the North Korean prison, just depending on God. I certainly hoped when I was in North Korea ... that someday I'd be able to come home and celebrate with the friends and family that have been praying, rooting for my release."
The married father-of-three has written about his story in a new book, "Not Forgotten: The True Story of My Imprisonment in North Korea", which is due to be released in the UK on July, 1.
A licensed preacher in the Presbyterian Church in America (PCA) and an ordained Southern Baptist pastor, Mr Bae has also been working with Youth With A Mission (YWAM) since 2005.