China and Russia eavesdrop on President Donald Trump as he uses his unsecure cellphone to "gossip, gripe or solicit" his friends' take on how he is doing, the New York Times reported on Wednesday, citing US intelligence agencies.

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, the paper said.