MERSIN, Turkey -- Rescuers raced on Sunday to rescue an American caver who had become trapped more than 1,000 metres (3,300 ft) underground in southern Turkey, moving him halfway to the surface.

Mark Dickey, 40, was on an international exploration expedition in the Morca cave in Mersin province's Taurus mountains when he began suffering from gastrointestinal bleeding at a depth of 1,040 metres.

More than 150 rescuers from Turkey and other countries have been working for days to rescue him from the country's third deepest cave.

"Our medical team is working really hard to try to keep Mark's condition as stable as possible. Since yesterday, we started lifting the stretcher and transporting him through the cave," Giuseppe Conti, European Cave Rescue Association technical commission chairperson, told reporters.

"We have to do it very carefully because we cannot risk any conditions worsening (for) Mark. So we must pay attention metre after metre. Currently, the stretcher is about ... 500 metres from the surface."

Dickey's fiancee, Jessica Van Ord, who was with him during the expedition, has been staying at the camp site and working with the rescue teams.

"A medical doctor will accompany him the whole way. Right now, Italian doctors are accompanying him along the route. Mark's medical condition right now is very good," said Tulga Sener, medical coordinator for the cave rescue commission.

Cenk Yildiz, Mersin provincial head of Turkey's AFAD disaster management authority, said Dickey would be brought out in two to three days "if they don't experience any problems".