A 95-year-old former North Korean soldier who spent decades imprisoned in the South will continue his campaign to return to the North, an activist says, after South Korean troops stopped his symbolic border march.

Flanked by activists and holding a North Korean flag, Ahn Hak-sop walked towards an inter-Korean bridge in the border town of Paju on Wednesday, demanding that South Korean authorities arrange his repatriation to the North, when soldiers stopped him at a checkpoint.

Ahn, who complained of knee pain during the incident, was taken to a hospital and was recovering at his home in Gimpo, near the capital city of Seoul, activist Cha Eun-jeong said.

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Cha said she expected Ahn to join a weekend protest in Seoul calling for his return to North Korea.

“He said it felt good to have an opportunity to speak his mind in front of journalists”, even though he was turned back by the soldiers, Cha said.

Ahn was born in what is now South Korea’s border island of Ganghwa in 1930, when the Korean Peninsula was under Japanese colonial rule.

Japan’s defeat in World War II liberated Korea, but the peninsula was then divided into a US-backed, capitalist South and a Soviet-supported, socialist North — a separation cemented by the devastating 1950-53 Korean War.

Ahn volunteered to fight for the North Korean army in 1952 but was captured by South Korean soldiers in April 1953, months before the fighting stopped with the armistice.

He was imprisoned for 42 years before receiving a special presidential pardon in 1995.

He had a chance to go to North Korea in 2000, when former South Korean president Kim Dae-jung repatriated 63 long-term unconverted prisoners following a historic summit with then-North Korean leader Kim Jong-il.

Ahn then chose to stay, vowing to campaign until US troops were withdrawn from the South.

Ahn expressed a desire to go to North Korea in July, a decision that was influenced by his fragile health and concern that his time was running out, Cha said.

South Korea’s government said earlier in August it had no immediate plans to push for the repatriation of the few remaining prisoners who desire to be sent to North Korea, and it’s unclear whether the North would accept them.