A Canadian pastor who was imprisoned in North Korea since 2015 returned to his home in Toronto on Saturday. Hyeon Soo Lim, North Korea’s longest-held Western prisoner in decades, was released last week on what was described as ‘sick bail.’ Prior to his release, he had complained of stomach pain and high blood pressure in letters to his family and friends. Lim was a pastor at one of Canada’s largest churches, Light Korean Presbyterian Church when he was sentenced to life imprisonment with hard labour during a mission trip to Rajin, North Korea.

He emigrated to Canada from South Korea almost 30 years ago and, according to his family, Lim has made more than 100 humanitarian trips to North Korea since 1997, which resulted in the establishment of a nursery, orphanage, and nursing home in Rajin. It was on one of these trips that he was arrested in January 2015 and accused of committing crimes against the state, which included trying to use religion to destroy the North Korean system and assisting foreign efforts to help people defect from North Korea.

Details on how the Canadian government secured his release have not been provided because, according to Prime Minister Trudeau, “operational security considerations” prevent the government from discussing the case further. However, it is common knowledge that the Canadian government sent a delegation to Pyongyang last week in a bid to secure the release of the 62-year-old pastor. These Canadian delegates returned to Canada with Lim on Saturday. Meanwhile, the Swedish embassy, which often serves as an intermediary for prisoners from nations with no formal diplomatic ties to North Korea, was also involved in securing his release. Moreover, it is unclear if the tension between North Korea and the United States over the former’s nuclear program contributed to Lim’s release.

Furthermore, getting Lim out of the isolated country proved to be even more urgent following the death of Otto Warmbier, an American student who died last month shortly after being released from a North Korean prison. Warmbier, who had been sentenced to fifteen years’ imprisonment for trying to steal a propaganda poster from his hotel, was returned to the U.S. in a vegetative state and died six days after his release from North Korea. However, North Korea is still holding three Americans and the U.S. State Department said last week that it would ban U.S. nationals from travelling to the country beginning in September.

With that said, Lim’s release comes in the wake of heightened tensions between North Korea and the U.S. For instance, on Tuesday, President Donald Trump threatened North Korea with “fire and fury” and North Korea said it was considering a military strike against the U.S. territory of Guam. However, Swedish Foreign Affairs Minister, Margot Wallstrom, suggested that Lim’s release supported their conviction that “dialogue is the best solution,” especially in the face of mounting tensions between Pyongyang and Washington. Similarly, other observers have noted that the release of Pastor Lim affirms the usefulness of diplomacy, even with a country like North Korea that is renowned for its human right violations.