HE MADE a mockery of himself on Saturday Night Live, but now it seems Donald Trump may have turned the joke into a reality.

President Donald Trump has been handing out his mobile number to world leaders and urging them to call him directly, an unusual invitation that breaks diplomatic protocol and is raising concerns about the security and secrecy of the US commander in chief’s communications, the Associated Press reports.

BREAKING: President Trump has been urging world leaders to call him on his cellphone, raising security and secrecy concerns. — The Associated Press (@AP) May 31, 2017

Trump has urged leaders of Canada and Mexico to reach him on his mobile, according to former and current US officials with direct knowledge of the practice. Of the two, only Canadian Prime Minister Justin Trudeau has taken advantage of the offer so far, the officials said.

Trump also exchanged numbers with French President Emmanuel Macron when the two spoke immediately following Macron’s victory earlier this month, according to a French official, who would not comment on whether Macron intended to use the line.

All the officials demanded anonymity because they were not authorised to reveal the conversations.

Neither the White House nor Trudeau’s office responded to requests for comment.

The news comes a year-and-a-half after the then-Presidential nominee appeared on Saturday Night Live parodying rapper Drake’s song, Hotline Bling, which runs with the line: “You used to call me on my cell phone”.

The video, which sees Mr Trump playing a tax man with bad dance moves, became an instant viral hit.

After Mr Trump’s recent news, the viral clip was reborn — and the internet had a field day.

"President Trump urging world leaders to call him on his private cellphone" pic.twitter.com/j3GO1Jk8nz — Olivia Nuzzi (@Olivianuzzi) May 31, 2017

"Trump urging world leaders to call him on his private cellphone" pic.twitter.com/igNy8hExcd — Polly Sigh (@dcpoll) May 31, 2017

And then I can tell you about my bigly toys and cool secret stuff. pic.twitter.com/4fLu5Ur0U1 — judy trujillo (@jetrujillo1027) May 31, 2017

The notion of world leaders calling each other up via their mobiles may seem unremarkable in the modern world. But in the diplomatic arena, where leader-to-leader calls are highly orchestrated affairs, it is another notable breach of protocol for a president who has expressed distrust of official channels.

The formalities and discipline of diplomacy have been a rough fit for Trump — who, before taking office, was easily accessible by mobile and viewed himself as freewheeling, impulsive deal-maker.

Presidents generally place calls on one of several secure phone lines, including those in the White House Situation Room, the Oval Office or the presidential limousine. Even if Trump uses his government-issued mobile, his calls are vulnerable to eavesdropping, particularly from foreign governments, national security experts say.

“If you are speaking on an open line, then it’s an open line, meaning those who have the ability to monitor those conversations are doing so,” said Derek Chollet, a former Pentagon adviser and National Security Council official now at the German Marshall Fund of the United States.

A president “doesn’t carry with him a secure phone,” Chollet said.

“If someone is trying to spy on you, then everything you’re saying, you have to presume that others are listening to it.”

"President Trump urging world leaders to call him on his private cellphone" pic.twitter.com/0aIZdQ7AFk — Lauren Werner (@LaurenWern) May 31, 2017

The caution is warranted even when dealing with allies. As German Chancellor Angela Merkel’s learned in 2013, when a dump of American secrets leaked by Edward Snowden revealed the US was monitoring her phone, good relations don’t prevent some spycraft between friends.

“If you are Macron or the leader of any country and you get the cellphone number of the president of the United States, it’s reasonable to assume that they’d hand it right over to their intel service,” said Ashley Deeks, a law professor at the University of Virginia who formerly served as the assistant legal adviser for political-military affairs in the U.S. State Department. The practice opens Trump up to charges of hypocrisy.

Throughout last year’s presidential campaign, he lambasted Democratic rival Hillary Clinton for using a private email server while she was secretary of state, insisting she should not be given access to classified information because she would leave it vulnerable to foreign foes.

world leaders be like: pic.twitter.com/LmsGPYE8tL — Dave McMahon (@4realtalk2010) May 31, 2017

Trump has struggled more than most recent presidents to keep his conversations with world leaders private. His remarks to Australian Prime Minister Malcolm Turnbull, Mexican President Enrique Pena Nieto and Russian diplomats have all leaked, presumably after notes of the conversations were circulated by national security officials.

It was unclear whether an impromptu, informal call with a foreign leader would be logged and archived. The Presidential Records Act of 1981, passed in response to the Watergate scandal, requires that the president and his staff preserve all records related to the office. In 2014, the act was amended to include personal emails.

But the law contains “blind spots” — namely, record-keeping for direct mobile communications, said Jonathan Turley, a professor at George Washington University Law School, who specialises in public interest and national security law.

Under Barack Obama, the first mobile phone-toting president, worries about cyber intrusions — particularly by foreign governments — pulled the president’s devices deep into the security bubble. Many of the functions on Obama’s BlackBerry were blocked, and a very small handful of people had his phone number or email address, according to former aides.

“Government sometimes looks like a big bureaucracy that has stupid rules, but a lot of these things are in place for very good reasons and they’ve been around for a while and determine the most effective way to do business in the foreign policy sphere,” said Deeks.

“Sometimes it takes presidents longer to figure that out.”