The United States has threatened to oppose Britain's sovereignty over the Falkland Islands if Andy Burnham does not increase defence spending, The Telegraph can reveal.

The proposal is among measures being drawn up by senior defence officials at the Pentagon as an incentive to hit Nato's 5 per cent spending pledge.

A senior US official told The Telegraph that Britain was likely to receive "special attention" in Washington's review of its allies' commitment to Nato, which will examine whether member nations have credible paths toward the target.