A Canadian pastor has spoken publicly for the first time since his release from imprisonment in North Korea last week, describing in detail the harsh conditions he endured while performing hard labour.

Hyeon Soo Lim, 62, spoke at length in Korean at the end of a Sunday service at his church in Mississauga, Ont., west of Toronto.

During the service, at Light Presbyterian Church, Lim sat at the front of the church, accompanied by his son and infant granddaughter.

Pastor Hyeon Soo Lim held his granddaughter during a church service at the Light Presbyterian Church in Mississauga, Ont., near Toronto, on Sunday. He later got up to address the congregation, speaking in Korean. (Frank Gunn/Canadian Press)

On Saturday, Lim was reunited with his family in Ontario after more than two years in detention in North Korea. The country originally sentenced him to death, but that sentence was commuted to a life of hard labour.

In a prepared statement in English, Lim said he was hospitalized four times, was forced to dig holes in frozen ground outside and had to break apart coal inside a facility.

Lim said he experienced "overwhelming loneliness" during his time in detention. In the statement, released before he started speaking at the church, he talked about the "difficult moments" he suffered.

Digging holes in frozen ground

"From the first day of my detainment to the day I was released, I ate 2,757 meals in isolation by myself. It was difficult to see when and how the entire ordeal would end," Lim said.

"During the winter, I had to dig holes that measured one metre wide and one metre deep. The ground was frozen. The mud was so hard that it took two days to dig one hole. It was incredibly challenging. My upper body was sweating; My fingers and toes were frostbitten. I also worked inside a coal storage facility, breaking apart coal," he said.

Pastor Hyeon Soo Lim arrives at his church in Mississauga, Ont., a day after returning to Canada. He was detained in North Korea for more than two years. 0:43

"In the spring and summer, I worked outside, eight hours a day, in the scorching sun."

Lim said the hard physical labour took a toll on his body and the first time he went to hospital it was for two months.

While I was labouring, I prayed without ceasing - Hyeon Soo Lim, Light Presbyterian Church pastor

To keep himself busy, he said he read more than 100 books on North Korea, read the Bible in English and Korean five times, memorized more than 700 Bible verses, and worshipped alone on 130 Sundays.

"While I was labouring, I prayed without ceasing," he said.

He said his moments of "discouragement, resentment and grumbling" turned into "courage, joy and thanksgiving."

Pastor thanks Canada, Sweden

Lim also thanked the Canadian and Swedish governments for securing his release, the church community for its prayers and his friends for their efforts to free him. Sweden is Canada's protecting power in North Korea.

Prime Minister Justin Trudeau, Foreign Affairs Minister Chrystia Freeland, Special Adviser Daniel Jean and former Foreign Affairs Minister Stéphane Dion were among the officials he thanked by name.

Lim, who was arrested in North Korea in 2015 and sentenced for alleged crimes against the state, was released last week on what the North Korean government called "sick bail" after a delegation headed by Jean travelled to North Korea.

His son, James Lim, told reporters in a news conference on Saturday that the family is thrilled that his father is now home.

Pastor Hyeon Soo Lim returned to his church in Mississauga, Ont., on Sunday after Canadian officials helped secure his release from North Korea 0:25

Lim himself did not appear at Saturday's news conference, but he walked away from the plane unaided. His son said his father appeared to be in "good health," though the family plans to arrange for a complete checkup. His son said Lim lost about 50 pounds during his incarceration.

When Lim was reunited with his family, he met his granddaughter, under a year old, for the first time, according to his son.

In a statement on Saturday, Global Affairs Canada said it celebrated his return to Canada.

"Canada has been actively engaged on Mr. Lim's case at all levels, and we will continue to support him and his family now that he has returned," the statement read.

Foreign Affairs Minister Chrystia Freeland said she is "deeply relieved" and "happy" that Lim has been released.

Freeland thanked the Swedish government for its work in helping to secure his freedom. She said his family worked tirelessly on his behalf, with the support of his congregation.

"I'm just so glad he is out of there. He is a very, very brave man," she said this week.

Went to North Korea in 2015 on a mission

Lim's release came nearly two months after U.S. college student Otto Warmbier died shortly after he was released from North Korea in a coma. Warmbier had been sentenced to 15 years of hard labour in March 2016 after being accused of stealing a propaganda poster.

Lim had travelled to North Korea in January 2015 as part of a regular humanitarian mission to North Korea where he supports a nursing home, a nursery and an orphanage.

Pastor Hyeon Soo Lin, second from right, of Mississauga, Ont., greets family after being released from a North Korean prison at an undisclosed location on Saturday. (Canadian Press)

Family and supporters said Lim had made more than 100 trips to North Korea since 1997 and that his trips were about helping people and were not political.

The Canadian government, in its travel advisory for North Korea, advises against all travel to the country "due to the uncertain security situation caused by North Korea's nuclear weapons development program and highly repressive regime."

The government maintains no office in the country. "The ability of Canadian officials to provide consular assistance in North Korea is extremely limited," it says.