President-elect Donald Trump floated to Canadian Prime Minister Justin Trudeau on Friday that maybe Canada should become the ’51st state.’

Fox News reported Monday night on new details from the impromptu Mar-a-Lago meeting, which was Trump’s first face-to-face get-together with a world leader since winning reelection on November 5.

Trudeau made a surprise trip to Palm Beach, Florida on Friday after Trump threatened last Monday to impose 25 percent tariffs on Canada, blaming the U.S.’s northern neighbor for some of the illegal immigrants who have flowed in.

During their sit-down, Trudeau told Trump he cannot levy a 25 percent tariff on Canada because it would completely kill the Canadian economy.

Trump replied – so your country can’t survive unless it’s ripping off the U.S. to the tune of $100 billion?

The president-elect then suggested to Trudeau that Canada become the 51st state, which caused the prime minister and others at the table to laugh nervously, Fox’s sources said.

Trump added that while prime minister is a better title, Trudeau could still be a governor.

The sources said that someone at the table suggested Canada would be a really liberal state, which cued laughter.

Trump then suggested that Canada could be divided into two states – a conservative and a liberal state.

He then told Trudeau if he didn’t stop people from flowing over the northern border, Canada could become one or two U.S. states, the sources said.

While the exchange prompted laughs, sources also told Fox that Trump gave a serious message to Trudeau about immigration enforcement.

Illegal crossing from Canada represent a much smaller number than the illegal foot traffic into the U.S. from Mexico – but Trump threatened both Canada and Mexico with 25 percent tariffs if actions weren’t taken.

In the same Truth Social post, he threatened an additional 10 percent in import taxes on China – due to the government not imposing a death penalty on drug dealers as was promised.

Part of Trump’s hardline policies are to stop the flow of the deadly Chinese-produced drug fentanyl into the United States.

A Canadian Broadcasting Corporation report from last week found that the U.S. Border Patrol had intercepted more than 21,000 migrants crossing into the U.S. from Canada during the first 10 months of the year.

In October alone, however, border agents apprehended more than 56,000 migrants coming over the southern border.

A majority of the illegal crossings from Canada – around 18,000 for the first 10 months of the year – are via the so-called Swanton Sector, which has seen a dramatic rise in illegal crossings over the past two years.

It’s the area east of the Great Lakes in New York, Vermont and New Hampshire.

Trump’s incoming ‘border czar,’ Tom Homan, is from this region – and will no doubt pay it some attention – and it’s part of Rep. Elise Stefanik’s district.

She’s been a top Trump ally on Capitol Hill and is due to become is ambassador to the United Nations.