Washington: When President Donald Trump calls old friends on one of his iPhones to gossip, gripe or solicit their latest take on how he is doing, US intelligence reports indicate that Chinese spies are often listening — and putting to use invaluable insights into how to best work the president and affect administration policy, current and former US officials said.

Trump’s aides have repeatedly warned him that his cellphone calls are not secure, and they have told him that Russian spies are routinely eavesdropping on the calls, as well. But aides say the voluble president, who has been pressured into using his secure White House landline more often these days, has still refused to give up his iPhones. White House officials say they can only hope he refrains from discussing classified information when he is on them.

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.

US spy agencies, the officials said, had learnt that China and Russia were eavesdropping on the president’s cellphone calls from human sources inside foreign governments and intercepting communications between foreign officials.

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 United States 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 hopes of using them to influence the president, the officials said.

Among those on the list are Stephen A. Schwarzman, the Blackstone Group chief executive who has endowed a master’s programme at Tsinghua University in Beijing, and Steve Wynn, the former Las Vegas casino magnate who used to own a lucrative property in Macau.

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.

Officials said the president has two official iPhones that have been altered by the National Security Agency to limit their capabilities — and vulnerabilities — and a third personal phone that is no different from hundreds of millions of iPhones in use around the world. Trump keeps the personal phone, White House officials said, because unlike his other two phones, he can store his contacts in it.