A North Korean pastor who was targeted and persecuted by the government for his Christian faith has said that after fleeing to America, life is "heaven" compared to the "hell" he experienced in the isolated country.

Choi Kwanghyuk, 55, fled North Korea several years ago and now lives in Los Angeles, CA: "There is an enormous difference between my life in North Korea and my life in the U.S," he told Fox News. "The life in North Korea is hell ... life in America is heaven."

Being a Christian in the officially atheist state where public worship is forbidden was incredibly dangerous, yet he felt compelled to share the gospel with others.

"We couldn't raise our voice during a service, we couldn't sing out loud during a worship ... that was hard," Choi said.. "Also, we had to hide so that other people could not see us."

While living in North Hamgyong province, Choi started an underground church, where congregants worshipped with only one Bible.

"There were about nine people," he said. "I couldn't do mission work because we had to keep it secret that we had a church. If that information had leaked, we could have faced the death penalty."

He added, "North Hamgyong province is very cold. In the winter, we would dig a big hole and store kimchi there. We sometimes had services there. In the summer, we had services in the mountain or by the river. I never heard the term 'underground church' until I got here [to the U.S.]."

In 2008, North Korean authorities arrested Choi, and threw him in prison where he was interrogated about his faith and routinely tortured.

Eventually, Choi decided to attempt to escape after learning he was to be sent to one of North Korea's notorious labor camps, where prisoners are subject to horrific forms of torture.

"I decided to escape because I thought that once they sent me to the other camp, they could eventually send me to the concentration camp or kill me," Choi recalled. "I was traveling back and forth between China and North Korea, but they kept searching for me, and I knew it could put my friends in danger too, so I left."

Choi finally escaped to neighboring China, and was granted asylum in the U.S. in 2013. He first lived in Dallas before eventually moving to Los Angeles.

Today, the pastor bears physical scars from his time North Korea, as he is unable to work as a result of the injuries he received while being tortured. Still, he is determined to tell the world about the human rights abuses in the oppressive country

"First of all, every human must have the right to freedom," he said. "There is no freedom in North Korea. By law, they have the freedom of religion and the freedom of the press, but the reality is very different."

North Korea, now ruled by Kim Jong Un, is ranked the most oppressive place for Christians in the world, according to Open Doors USA. It's estimated that between 30,000 and 70,000 Christians are held in "kwanliso," or political labor camps.

"[Choi's] statements describing oppression, as well as his report of imprisonment for owning a Bible or practicing faith, align with everything we know about North Korea," Opens Doors President David Curry told Fox News. "Rated the worst place for the persecution of Christians, North Korea treats Christians horrendously and registers them as 'enemies of the state' for their faith."

Kim Chung-seong, a defector from North Korea who spoke at the World Summit in Defense of Persecuted Christians in May, said the government fears the spread of the gospel.

"The one thing that the North Korean regime fears the most, and is afraid of, is the spreading of the Gospel," he said, according to the Catholic News Agency. "Because the Bible and the Gospel speaks the truth. Once the light shines in the dark room, there is light in the room."

"They [the government] will do anything to prevent the spread of the Gospel in North Korea," he said, adding that the government even set up a "façade" organization called the Korea Christian Association to lure the believers.

"But] as you can see, we cannot block the sunlight with our hand," he said.