How Safe Is Donald Trump’s Move To Hand Out Cellphone Number To World Leaders?

President Donald Trump has asked world leaders to contact him directly on his cellphone, raising security concerns, the Associated Press (AP) reported Tuesday. So far, only Canadian Prime Minister Justin Trudeau made use of the offer, the report added.

Former and current U.S. officials told the AP that Trump handed out his cellphone number to Canadian and Mexican leaders. He even shared his number with French President Emmanuel Macron when the two spoke after Macron’s presidential win earlier this month, a French official told the AP. However, it remained unclear whether the French president called his American counterpart on his number.

Read: Trump Android Cell Phone: Unsecure Smartphone Use Should Be Investigated, Congressman Says

The AP noted presidents’ calls are often done through secure phone lines such as those in the White House Situation Room, the Oval Office or the presidential limousine. Trump is at the risk of being eavesdropped even when using government-issued cellphone.

“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,” Derek Chollet, a former Pentagon adviser and National Security Council official told the AP, adding a president “doesn’t carry with him a secure phone.”

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

According to a May 25 report from Axios, the 70-year-old president currently uses an iPhone, which has only one app — Twitter.

After being elected president, Trump was reluctant to hand over his Android device — identified as Samsung Galaxy S3 — but ultimately gave up on the phone less than a day before he assumed the office after being urged by security agencies to do so. The Secret Service is reported to have given the president a secure, encrypted cellphone before the inauguration.

Last November, the New York Times reported then-president elect’s hesitance to give away his cellphone.

“He is worried, his aides say, that he will not be able to keep his Android phone once he gets to the White House and wonders aloud how isolated he will become — and whether he will be able to keep in touch with his friends — without it as president,” the newspaper reported at the time.

On Jan. 20, the AP reported one of its reporters called Trump after his meeting with intelligence officials about Russia interfering in the 2016 election, but the call was not answered. However, about an hour later Trump called him back on the unknown number.

In 2008, when Barack Obama was the president-elect, National Security Agency set up him BlackBerry device, which was had extra layers of encryption.

According to a Jan. 19 report from Recode, the president’s phone should not have any internet connection. Matthew Green, a cryptographer and professor of computer science at John Hopkins Information Security Institute, told Recode at the time anything connected to the internet is prone to cyberattacks so the president’s device should not be connected to the internet. Moreover, any commercial-grade phones carried by Trump or his aides could be kept out of high-level meetings as there are chances those devices’ microphone could turned through certain hacks, Tom Lowenthal, a digital security technologist at the Committee to Protect Journalists, told the news outlet.