Updated

Three global warming researchers stranded in the North Pole by cold weather were holding out hope Wednesday as a fourth plane set off in an attempt deliver them supplies.

The flight took off during a break in bad weather after “brutal” conditions halted three previous attempts to reach the British explorers who said they were nearly out of food, the Agence France-Presse reported.

“We’re hungry, the cold is relentless, our sleeping bags are full of ice,” expedition leader Pen Hadow said in e-mailed statement. “Waiting is almost the worst part of an expedition as we’re in the lap of the weather gods.”

Hadow, Martin Hartley and Ann Daniels began an 85-day hike to the North Pole on February 28 to measure sea ice thickness, the AFP reported.

With bad weather hampering supply flights, the team is was down to half-rations, battling desperate sub-zero temperatures and unable to proceed, the AFP reported.

"It'll be a relief to get our new supplies," Hadow said in a statement Wednesday. "Until (the plane) does arrive, we need to conserve energy and can't really move on."

The expedition now expects to arrive at the North Pole in late May.

Click here for more on this story from the Agence France-Presse.