Greece's finance minister said Greece would not be able to service its debt in the short-term so would need a haircut, or debt restructuring, he told Germany's Stern magazine.

"If a debt can no longer be paid off then that leads to a haircut," Yanis Varoufakis said in a pre-publication copy of the interview made available on Wednesday.

"What is critical is that Greece's debt cannot be paid off in the near future," he said.