Trump threatens Canada with staggering bill for Golden Dome if they refuse to comply with his request

US president Donald Trump has warned Canada it'll be slapped with a staggering bill for his controversial Golden Dome defence system if it refuses to comply with his request.

Last week (20 May), Trump revealed the concept or the $175 billion (£130 billion) missile defence system, explaining it would be able to shield the US from the threat of 'foreign missile attacks'.

However, the pricey system has been criticised by China, which has accused Trump of militarising space and fanning the flames of a global arms race.

But according to Trump, Canada is keen to join.

Donald Trump revealed the concept or the $175 billion (£130 billion) Golden Dome missile defence system last week (JIM WATSON/AFP via Getty Images)

Taking to his own social media platform Truth Social on Tuesday (27 May), the 78-year-old posted unfounded claims that Canada 'very much wants to be part of' what he has dubbed America's 'fabulous' Golden Dome system.

Trump went on to declare that Canada would need to cough up billions of dollars in order to be part of the expensive missile defence system - but it could do so for free should it give up its sovereignty and become the US' 51st state.

"I told Canada, which very much wants to be part of our fabulous Golden Dome System, that it will cost $61 Billion Dollars if they remain a separate, but unequal, Nation, but will cost ZERO DOLLARS if they become our cherished 51st State," Trump penned.

He added: "They are considering the offer!"

It came after King Charles III and Queen Consort Camilla landed in Canada amid the tensions between the nation - of which Charles is the head of state - and the United States.

As we know, Trump has launched a trade war against his country's neighbour and made threats to annex Canada as America’s 51st state.

During the royal family visit, Canada’s parliament hosted Charles for a rare royal speech in which he emphasised the nation's sovereignty in 'dangerous and uncertain' times.

Trump has since threatened Canada with a staggering bill for the Golden Dome if they refuse to comply with his request (Andrew Harnik/Getty Images)

"Today, Canada faces another critical moment. Democracy, pluralism, the rule of law, self-determination and freedom are values which Canadians hold dear, and ones which the Government is determined to protect," he said.

Charles continued: "The system of open global trade that, while not perfect, has helped to deliver prosperity for Canadians for decades, is changing. Canada’s relationships with partners are also changing.

"We must be clear-eyed: the world is a more dangerous and uncertain place than at any point since the Second World War.

"Canada is facing challenges that are unprecedented in our lifetimes."

The King went on to make reference to Canada's prime minister, Mark Carney, and Trump's efforts to 'define a new economic and security relationship between Canada and the US, rooted in mutual respect and founded on common interests, to deliver transformational benefits for both sovereign nations'.

"In parallel, the Government is working to strengthen its relationships with reliable trading partners and allies around the world, recognising that Canada has what the world needs and the values the world respects," he added.

Carney has previously insisted that his country is 'not for sale, ever' when asked about what he thinks of Trump's proposition.