A Canadian pastor who is serving a life sentence in a North Korean prison, says he spends eight hours a day, six days a week digging holes in a prison orchard.

Rev. Hyeon Soo Lim, a pastor with the Light Korean Presbyterian Church in Mississauga, Ont., was sentenced last December, for what the North Korean Supreme Court called crimes against the state. These included trying to use religion to destroy the state, disseminating negative propaganda about North Korea to Koreans overseas, and harming the dignity of the supreme leadership.

Lim described his current living conditions in an interview with CNN. In the interview, he was forced to answer only in Korean, even though he speaks English.

He said he is constantly being watched by two guards, and has no contact with his family or parishioners back home.

Lim, who is in his 60s, said he's getting used to the hard labour, and says he gets regular medical care and three meals a day.

His family said he travelled to North Korea in January, 2015, as part of a humanitarian mission. They said he has travelled to the state more than 100 times since 1997, and that his trips are not political in nature.

North Korea has strict rules against any religious or missionary activity.

Lim said in the interview that he has asked for a Bible, and continues to pray every day for the people of North Korea, and for the reunification of North and South Korea.

With files from The Canadian Press