A Seoul court sentenced a progressive South Korean pastor on Friday to five years in jail for unauthorized travel to North Korea, where he lauded the Pyongyang regime.

Prosecutors had demanded a 10-year jail term.

Rev. Han Sang-ryol, a pro-unification activist, was arrested and indicted last summer immediately after he crossed the heavily-fortified Korean border back to the South by foot. During his more than two-month stay in the communist state, the 61-year-old pastor gave a series of speeches praising its regime and denouncing the Lee Myung-bak administration in the South.

South Korea's National Security Law prohibits citizens from going to the North without prior authorization and from participating in any acts that sympathize with Pyongyang.

"The defendant went to the North without the Unification Ministry's approval, and he would have been aware that his activities will be extensively reported by the North's media for the regime's propaganda," the Seoul Central District Court said in a ruling. "As a matter of fact, he did support the North's regime and made remarks praising juche (self-reliance) principle and seongun (military first) politics," it said, referring to Pyongyang's two backbone ideologies.

The two Koreas are technically still at war after their 1950-53 conflict ended in a cease-fire, not a peace treaty.

Han entered Pyongyang by air on June 12 and returned on Aug. 20 by walking across the border village of Panmunjom. He made the trip when relations between the two Koreas were at their lowest ebb in years after the South condemned the North over the deadly sinking of its warship Cheonan in March.

In the packed courtroom, Han, bald and bearded, said "Hurray to unification of Koreas" with a smile. The presiding judge Kim Yong-dae replied, "That's well understood."

Following the ruling on the pastor, the same court sentenced Han's 53-year-old brother to a one-and-a-half year jail term, suspended for two years, for his anti-U.S. activities and for sympathizing with the communist nation.

Han Choong-mok, a co-leader of a progressive group of unification activists with the pastor, was indicted in August of last year on charges of leading a dozen outdoor rallies calling for the withdrawal of U.S. troops in South Korea, the removal of the statue of U.S. general Douglas MacArthur, who led U.N. forces in the South during the Korean War, and distributing reports in favor of Pyongyang's nuclear tests and missile launches from 2005-2009.

About 28,500 American troops are currently stationed in South Korea to deter threats from the North. (Yonhap News)