"We will stand behind ...the savers in Icesave to make sure that they get their money back," Darling told BBC television. "I wouldn't normally do this... but these are exceptional times."
"I, as the Chancellor of the Exchequer (finance minister) cannot have a situation where we have British depositors being left this way because of what has gone on in Iceland."
Iceland's Prime Minister Geir Haarde warned on Tuesday that his country was facing a risk of "national bankruptcy" as the global banking crisis threatened to overwhelm the island nation.
"It really is quite extraordinary when you get a country like Iceland which is defaulting on its obligations," Darling said. "We're going to pursue them with vigour ... you really can't have a situation like this where countries simply default," Darling said.