Lim was imprisoned by Pyongyang in January 2015 for carrying out “subversive activities,” a charge steadfastly denied by Ottawa which sent a high-level delegation this week to secure his release.

The missionary finally returned home on Saturday, with his captors citing clemency on medical grounds.

He appeared slightly frail but in good spirits as he returned to his congregation at the Light Korean Presbyterian Church in Mississauga, a Toronto suburb.

Wearing a black suit and tie with a white shirt, the pastor sat alongside his son in the first row of worshippers. His granddaughter, who was born while he was away, perched on his knees.

He told the congregation: “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.

“During the winter, I had to dig holes that measured one meter wide and one meter 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.”

The Canadian government has also thanked Sweden for its role in securing Lim’s release, which comes as the United States and North Korea are engaged in a standoff after Pyongyang successfully tested two intercontinental ballistic missiles.

US President Donald Trump raised the stakes this week by vowing to rain down “fire and fury” on the authoritarian state, which is presently holding three American citizens.

At the time of his arrest, members of the close-knit circle of ethnic Korean missionaries in Canada and the United States called Lim one of the most influential Christian missionaries operating in North Korea.

He had visited the country dozens of times, working with orphanages and nursing homes.

But some projects he worked on, including a noodle plant and flour mills, were linked to associates of Jang Song-Thaek, the purged uncle of leader Kim Jong-un. Jang was arrested and executed for treason in December 2013.

A number of Christian missionaries - mostly ethnic Koreans who are US citizens - have been arrested in the past, with some of them only allowed to return home after intervention by high-profile US political figures.

It was Lim’s first public appearance since his return to Canada on Saturday.

“Reverend Lim’s release was a miracle, work of God,” said the Korean church’s founder, emeritus pastor Chai Hoon Park.

Park said Lim told him late on Saturday that he thought he would die as a martyr in North Korea and only learned of his release 10 minutes before he was let go.

“’They told me to go get changed. Then I was turned over to the Canadian delegation,’” Park quoted Lim as telling him.

Additional reporting by Reuters