THE White House has denied claims US President Donald Trump has taken an extraordinary step to recoup the “vast sums of money” he believes other countries owe the United States.

According to The Sunday Times, the President handed German Chancellor Angela Merkel a bill for more than $490 billion which he believes his country has been short-changed over military alliance NATO.

The invoice was reportedly presented at the leaders’ meeting last week, in which the President apparently refused to shake Ms Merkel’s hand during a stage photo opportunity.

White House press secretary Sean Spicer said on Monday the Times story was “not true”.

After that meeting, Mr Trump singled out a number of countries in the NATO alliance, including Germany, over their defence contributions claiming the US had been forced to bear the brunt and pick up the tab.

On Twitter, he declared Germany owed “vast sums of money to NATO” and said the US “must be paid more for the powerful, and very expensive defence it provides to Germany”.

Despite what you have heard from the FAKE NEWS, I had a GREAT meeting with German Chancellor Angela Merkel. Nevertheless, Germany owes..... — Donald J. Trump (@realDonaldTrump) March 18, 2017

...vast sums of money to NATO & the United States must be paid more for the powerful, and very expensive, defense it provides to Germany! — Donald J. Trump (@realDonaldTrump) March 18, 2017

According to a statement from one German minister, the country won’t be playing along with Mr Trump’s plan, describing reported efforts to claw back the cash as “outrageous”.

“The concept behind putting out such demands is to intimidate the other side, but the chancellor took it calmly and will not respond to such provocations,” the unnamed minister told The Times.

The country’s defence minister Ursula von der Leyen went even further, saying definitively there was “no debt account at NATO”.

“Defence spending also goes into UN peacekeeping missions, into our European missions and into our contribution to the fight against ISIS terrorism” she said in a statement.

Mr Trump is pushing the country and others to invest 2 per cent of their GDP in defence.

He reportedly counted the invoiced amount by adding the amount by which German defence spending had fallen short of the 2 per cent target, plus interest, for each year since 2002 when the previous Chancellor committed to higher defence spending.

The abrupt billing strategy has been dismissed by experts, including the US’s former NATO representative Ivo Daalder.

1/ Sorry, Mr. President, that’s not how NATO works. The US decides for itself how much it contributes to defending NATO. pic.twitter.com/8svkzRBEQb — Ivo Daalder (@IvoHDaalder) March 18, 2017

Also, I think we now know his "plan" to get Mexico to pay for the wall. — Josh Barro (@jbarro) March 26, 2017

“Sorry Mr President, that’s not how NATO works. The US decides for itself how much it contributes to defending NATO,” he said in a tweet, followed by a handy explanation of NATO funding for the president.

Business journalist Josh Barro wrote: “I think we know his ‘plan’ to get Mexico to pay for the wall.”