United States President Donald Trump has broken protocol by urging world leaders to contact him on his cellphone, unidentified officials told AP. Trump is believed to have shared his cellphone number with Canadian Prime Minister Justin Trudeau, Mexican President Enrique Peña Nieto and French President Emmanuel Macron. Observers are concerned that US president’s actions are putting his office at risk.

Trudeau is purportedly the only one to have taken him up on the offer. Neither the White House nor Trudeau’s office has replied to requests for a comment, the news agency said.

Observers have criticised the controversial President’s move as it is a breach of diplomatic protocol, where world leaders communicate through secure lines with a scheduled approach. “If you are speaking on an open line, then it is an open line, meaning those who have the ability to monitor those conversations are doing so,” Derek Chollet, a former Pentagon adviser and National Security Council official told AFP.

The development gains significance as Trump had rebuked his rival presidential Democratic candidate Hillary Clinton for allegedly using a private email server while she was secretary of state. The Federal Bureau of Investigation had later said Clinton was not guilty of any criminal wrongdoing with respect to her private email server.