News of George Osborne's post-election budget has reportedly reached the White House and prompted President Barack Obama to praise the UK as the US's "primary partner on the world stage".

The leader of the free world gave the compliment to David Cameron over the phone after the government promised to meet Nato's 2% of GDP per year defence pledge, according to Number 10.

Downing Street also apparently revealed that Obama described the move as a "significant signal", a sign Osborne's announcement strengthened the so-called "special relationship" between the Western powers.

The latest comments from the commander in chief mark a shift in tone from the critical remarks Cameron faced from a top US general in the run-up to the election.

Previously, General Odierno, the chief of staff of the US Army, said he was "very concerned about the GDP investment in the UK".

"In the past we would have a British army division working alongside an American division. Now it might be a British brigade inside an American division, or even a British battalion inside an American brigade," he told The Telegraph.

Odierno issued the warning after coalition government ministers failed to commit to meeting the 2% marker as the election loomed.

A former Nato commander told IBTimes UK at the time that Britain's political parties had committed an "abdication of responsibility" by not agreeing to the threshold.

"It demonstrates to me that they don't think or don't understand the importance of committing to 2%," said Sir Richard Shirreff.

"[The spending target] is a remedy and can put right many of the gambles that have been taken in the last 10 years after successive resource driven defence reviews, which have successfully cut away the capability of the armed forces."

But now Osborne has committed to the target in his emergency budget, putting some Tory backbenchers' minds at ease, questions surround how the chancellor is going to pay for the move.

"For months and months, Tory ministers failed to guarantee that they would meet the 2% target, yet within weeks of forming a new government have been able to do just that. So, how did they do it?," Labour's shadow defence minister queried.

Kevan Jones, writing for the LabourList, added: "It is clear then that the Ministry of Defence has not become a land of milk and honey overnight.

"Crucially, their latest announcement does not mean that the defence secretary or the prime minister can avoid facing tough questions over this year's vital Strategic Defence and Security Review (SDSR)."