A Canadian pastor who was arrested in North Korea last year for allegedly plotting to overthrow the state has been hospitalized because of poor health.

According to Canadian diplomats, Hyeon Soo Lim, pastor at Light Presbyterian Church in Toronto, has been receiving treatment in the hospital since August, UPI reported. His family has been informed of his deteriorating health.

In April, Canada sent a delegation to visit Lim in Pyongyang but did not disclose the details of their visit for Lim’s protection.

"The government of Canada is concerned for Mr. Lim's rights and well-being," Joseph Pickerill, spokesman for Foreign Minister Stéphane Dion, said, according to CBC News. "Consular officials are providing assistance to Mr. Lim and his family. We are grateful that we were able to visit him."

Canada has been negotiating the pastor’s release but it admits the process will not be easy.

Lim had gone missing in North Korea in January 2015. The following month, news of his arrest broke out. North Korean officials accused him of committing crimes against the state.

In August, North Korean state news released a video of Lim confessing to the said crimes.

“The worst crime I committed was to rashly defame and insult the highest dignity and the system of the republic,” Lim said in the video, adding that he planned to “overturn its social system by taking advantage of the hostile policy against it sought by the South Korean authorities and set up a base for building a religious state,” The Guardian reported.

However, persecution watchdog Release International said he appeared to be reading from a script, and there are suspicions that Lim had been coerced into confessing the crimes.

On December of the same year, after a brief trial, Lim was sentenced to life imprisonment with hard labor. The pastor is in his 60s, and many people, including his family, expressed concerns for his health.

The members of his church in Toronto are petitioning the Canadian government to intervene for Lim’s sake.

"We know that in both cases the highest level of government officials, including Prime Minister Justin Trudeau himself, were instrumental in securing the release of these fellow Canadians," the church said in a statement, referring to citizens who had been detained in other countries and had been set free. "We urge the Canadian government to demonstrate the same attention and determination when engaging in diplomatic talks with the North Korean officials."

Lim had been involved in humanitarian work in North Korea, where he helped establish orphanages and nursing homes, for almost 20 years. He had traveled to the country more than 100 times before his arrest.

Lim, in an interview with CNN, said he worked eight hours a day, six days a week, in the labor camp. He dug holes for planting apple trees.

"I hope I can go home some day," Lim said. "Nobody knows if I will ever go home, but that is my hope. I miss my family. I am longing to see them again, and my congregation."