As many as eight of the 19 South Korean hostages held by the Taliban in Afghanistan could be freed on Wednesday, a Taliban representative has said.

A spokesman for the group, Qari Mohammad Bashir, told the Reuters news agency early Wednesday that a first batch of South Korean Christian volunteers kidnapped nearly six weeks ago will be released.

"Our decision is today," Reuters quoted Bashir as saying on Wednesday. "We are trying to start the work today."

South Korean presidential spokesman Cheon Ho-sun said the release was "on the condition that South Korea withdraws troops by the end of year and South Korea suspends missionary work in Afghanistan," he said.

Qari Yousef Ahmadi, another Taliban spokesman, said South Korean and Taliban delegates at face-to-face talks Tuesday in the central Afghan town of Ghazni had "reached an agreement" to release the captives.

The Taliban said it would hold a news conference later to explain the deal.

South Korea has already said it planned to withdraw its troops by the end of the year. Some 200 South Korean soldiers have been deployed in Afghanistan for reconstruction efforts, not combat.

"We welcome the agreement to release 19 South Koreans," said Cheon.

Taliban militants seized 23 South Korean members of a Christian aid group travelling by bus from Kabul to Kandahar on July 19. They had demanded the Afghan government and the U.S. military release Taliban prisoners in exchange for the safe return of the South Koreans.

In late July, they shot and killed two male captives. In mid-August, they released two female hostages.

With files from the Associated Press