Canadian diplomats were allowed to meet a Canadian pastor soon after he was sentenced to life in prison in North Korea last week and found him in good spirits and health, a church spokeswoman said on Sunday.

Hyeon Soo Lim, held by North Korea since February, was sentenced to hard labour for life for subversion on Wednesday, a ruling Canada called "unduly harsh".

Lim, a Canadian citizen, had been doing humanitarian work in North Korea since 1997 and had visited the isolated country more than 100 times, according to his Toronto church, the 3,000-member Light Korean Presbyterian Church.

He cried when Canadian diplomats relayed his son's message that "we're all proud of you", church spokeswoman Lisa Pak said.

Pak said after an emotional prayer meeting for Lim, which drew more than 1,000 churchgoers, that two consular officials from Canada's embassy in Seoul and a translator met Lim on Friday. She also confirmed he had received medication for an unspecified health condition.

The church began a petition at the prayer meeting asking UN Secretary-General Ban Ki-moon, who is arranging a potential visit to North Korea, to seek Lim's release.

North Korea's highest court said Lim had attempted to overthrow the government and undermine its social system with "religious activities" for the past 18 years, China's official Xinhua news agency reported.

He is the only Western citizen known to be held currently in North Korea.

North Korea had previously sentenced Korean-American missionary Kenneth Bae to 15 years of hard labour but released him last year after holding him for two years.