The American speleologist trapped 1,000 meters deep in a cave in southern Turkey has recorded a message in which he says he is fine but urgently needs “serious help” to get to the surface.

40-year-old Mark Dickie was exploring the Morcha cave network with an international team of colleagues when he suffered internal bleeding.

“Good morning, I’m Mark Dickie,” the speleologist, looking pale and wearing warm clothes, can be heard saying in the video released by the Turkish presidency.

“As you can see, I’m standing up, I’m alert, I’m talking, but I’m still not cured and I’m going to need serious help to get out of here,” he continues, thanking the Turkish authorities, rescuers and “the speleology world” that rushed to his side of.

More than 150 trained rescuers, and about 20 teams from Turkey and abroad went to help Dicky, according to the Turkish Speleology Federation.

“The quick response of the Turkish government to give me the medical help I needed I think saved my life,” he added, explaining that he was “very close to the end” when his fiancee, Jessica, appeared in front of him carrying medicine. The rescuers managed to send blood to the cave for him to receive a transfusion.

This was “a wonderful opportunity to show how well people can work when they work together,” he added.

Footage from the rescue operation shows the rescuers talking to Dickie and setting up a makeshift camp in the cave room where he is. Other groups have camps just outside Turkey’s third-deepest cave.

Tulga Sener, the head of the rescue mission’s medical team, said Dicky’s condition is stable and his vital signs are normal. Three doctors will accompany him on his way out of the cave. The rescue operation has been divided into seven divisions, each assigned to a team – all from different countries – because of its complexity, said Recep Salci, the head of Turkey’s AFAD disaster management agency. “Of course, this is not a cave that one goes for a walk in. It takes a caver 12 hours to go down it and 16 hours to come back up,” he explained.

The operation may take several days to complete and explosives may be used to widen some narrow passages, he added.