Trump keeps the personal phone because, unlike his other two phones, he can store his contacts in it, White House officials say. Trump typically relies on his mobile phones when he does not want a call going through the White House switchboard and logged for senior aides to see, his aides said. Many of those to whom Trump speaks most often on one of his mobile phones, such as hosts at Fox News, share his political views, or simply enable him to express his sense of grievance about any number of subjects. Administration officials said Trump's long-time paranoia about surveillance - well before coming to the White House he believed his phone conversations were often being recorded - gave them some comfort that he was not disclosing classified information on the calls. The phone guy: President Donald Trump speaks to then Australian prime minister Malcolm Turnbull on a landline in the Oval Office of the White House on January 28, 2017. Credit:AP They said they had further confidence he was not spilling secrets because he rarely digs into the details of the intelligence he is shown and is not well versed in the operational specifics of military or covert activities.

Trump is supposed to swap his two official phones every 30 days for new ones but rarely does, bristling at the inconvenience. White House staff members are supposed to set up the new phones exactly like the old ones, but the new iPhones cannot be restored from back-ups of his old phones, because doing so would transfer over any malware. Loading The President is also famously indiscreet. In a May 2017 meeting in the Oval Office with Russian officials, he shared highly sensitive intelligence passed to the US by Israel. He also told the Russians that James Comey, the former FBI director, was "a real nut job" and that firing him had relieved "great pressure". Attacks on Hillary The issue of secure communications is fraught for Trump. As a presidential candidate, he regularly attacked his Democratic opponent, Hillary Clinton, during the 2016 campaign for her use of an unsecured email server while she was secretary state, and he basked in chants of "lock her up" at his rallies.

But, Trump's lack of tech savvy has alleviated some other security concerns. He does not use email, so the risk of a phishing attack such as those used by Russian intelligence to gain access to Democratic Party emails is close to nil. The same goes for texts, which are disabled on his official phones. His Twitter phone can connect to the internet only over a Wi-Fi connection, and he rarely, if ever, has access to unsecured wireless networks, officials said. But the security of the device ultimately depends on the user, and protecting the President's phones has sometimes proved difficult. Last year, one of Trump's mobile phones was left behind in a golf cart at his club in Bedminster, New Jersey, causing a scramble to locate it, according to two people familiar with what took place. Loading Trump's use of his iPhones was detailed by several current and former officials, who spoke on the condition of anonymity so they could discuss classified intelligence and sensitive security arrangements. The officials said they were doing so not to undermine Trump, but out of frustration with what they considered the President's casual approach to electronic security.

The officials said that US spy agencies had learnt from human sources inside foreign governments and intercepting communications between foreign officials that China and Russia were eavesdropping on the President's mobile phone calls. Marriage of lobbying and espionage The officials said they have also determined that China is seeking to use what it is learning from the calls - how Trump thinks, what arguments tend to sway him and to whom he is inclined to listen - to keep a trade war with the US from escalating further. In what amounts to a marriage of lobbying and espionage, the Chinese have pieced together a list of the people with whom Trump regularly speaks in the hopes of using them to influence the President, the officials said. They added that the Trump friends were most likely unaware of any Chinese effort.

Among those on the list are Stephen Schwarzman, the Blackstone Group chief executive who has endowed a master's program at Tsinghua University in Beijing; and Steve Wynn, the former Las Vegas casino magnate who used to own a lucrative property in Macau. Loading Christine Anderson, a spokeswoman for Blackstone, declined to comment on Chinese efforts to influence Schwarzman but said that he "has been happy to serve as an intermediary on certain critical matters between the two countries at the request of both heads of state". L. Lin Wood, a lawyer for Wynn, said his client was retired and had no comment. Russia is not believed to be running as sophisticated an influence effort as China because of Trump's apparent affinity for President Vladimir Putin, a former official said.

The Chinese and the Russians "would look for any little thing - how easily was [Trump] talked out of something, what was the argument that was used", said John Sipher, a 28-year veteran of the CIA who served in Moscow in the 1990s and later ran the agency's Russia program. One official said the Chinese were pushing for the friends to persuade Trump to sit down with President Xi Jinping as often as possible. The Chinese, the official said, correctly perceive that Trump places tremendous value on personal relationships, and that one-on-one meetings yield breakthroughs far more often than regular contacts between Chinese and US officials. Whether the friends can stop Trump from pursuing a trade war with China is another question. Mobile phones vulnerable Apple declined to comment on the US President's iPhones although none of the phones are completely secure and are vulnerable to hackers who could remotely break into them.

In addition, calls made from the phones can be intercepted as they travel through the mobile phone towers, cables and switches that make up national and international mobile phone networks. Calls made from any mobile phone - iPhones, Androids, old-school Samsung flip phones - are vulnerable. Loading Intercepting calls is a relatively easy skill for governments. US intelligence agencies consider it an essential tool of spycraft, and they routinely try to tap the phones of important foreign leaders. In a diplomatic blow-up during the Obama administration, documents leaked by Edward Snowden, a former contractor for the NSA, showed that the US government had tapped the phone of Chancellor Angela Merkel of Germany. Foreign governments are well aware of the risk, and so leaders such as Xi and Putin avoid using mobile phones when possible. Former president Barack Obama was careful with mobile phones. He used an iPhone in his second term, but it could not make calls and could receive email only from a special address that was given to a select group of staff members and intimates.

It had no camera or microphone and could not be used to download apps at will. Texting was forbidden because there was no way to collect and store the messages, as required by the Presidential Records Act. "It is a great phone, state of the art, but it doesn't take pictures, you can't text. The phone doesn't work, you know, you can't play your music on it," Obama said on The Tonight Show Starring Jimmy Fallon in June 2016. "So basically, it's like - does your three-year-old have one of those play phones?" When Obama needed a mobile phone, the officials said, he used one of those of his aides. With Trump, though, the Chinese and the Russians are listening, and learning. The New York Times