Afghan villagers on Sunday found the body of a German aid worker kidnapped in southern Afghanistan, a police chief said, while a delegation of South Korean officials arrived here only hours before a purported evening deadline set for 23 Korean hostages.

Afghan and U.S. troops, meanwhile, "surrounded" an area in southern Ghazni province where officials believe the South Koreans are being held, said Gen. Mohammad Zahir Azimi, the Defense Ministry spokesman.

"As soon as we receive the order, we will start the operation," Azimi said.

The body of the German was found in southern Wardak province, where two Germans and five Afghans were kidnapped on Wednesday, said provincial police chief Mohammad Hewas Mazlum.

A purported Taliban spokesman on Saturday said militants shot and killed the Germans because Germany hadn't pledged to pull its 3,000 troops from Afghanistan. But Afghan and German officials said intelligence indicated that one died of a heart attack and the other was still alive.

Mazlum said he did not immediately know the cause of death of the German whose body was recovered.

The eight-man South Korean delegation planned to meet with President Hamid Karzai and Afghanistan's foreign and interior ministers, said Sidney Serena, a political affairs officer at the Korean Embassy here.

A senior South Korean official said the team was negotiating with the Taliban through intermediaries. The official spoke on condition of anonymity because of the sensitivity of the issue.

Qari Yousuf Ahmadi, who claims to speak for the Taliban, has said the hard-line militia would release the 23 Koreans in exchange for the freedom of 23 Afghan prisoners. The militants kidnapped the South Koreans on Thursday while they were riding on a bus from Kabul to the southern city of Kandahar.

Ahmadi has said that 7 p.m. (1430 GMT) Sunday was the deadline for the Afghan government to agree to the trade. The government hasn't commented on the purported offer.

U.S. and Afghan forces, meanwhile, moved into the region where the Koreans are thought to be.

"We will only launch rescue operations or military action at the request of the Afghan and Korean governments," said U.S. Lt. Col. David Accetta. "We do not want to jeopardize the lives of the Korean civilians, and we expect that the governments of Korea and Afghanistan can secure their release peacefully through negotiations."

Serena said the 23 South Koreans, including 18 women, work at an aid organization called the Korea Foundation in Kandahar.

Though the South Koreans have been reported to be Christians, Serena said the embassy "strongly denies" that they were carrying out any sort of religious activities.

The chief of the South Korean parliamentary defense committee, Kim Sung-gon, said Sunday in Seoul that the country's 210 troops in Afghanistan have started preparations to pull out of the country by the end of the year as planned.

The Defense Ministry stressed that the process had begun well before the Taliban demanded the withdrawal of South Korean troops from the war-ravaged country.