BIARRITZ, France (AFP) - Did Donald Trump really have lunch with someone impersonating France's President Emmanuel Macron on Saturday? No - but the US president did accidentally tweet that he had.

"Just had lunch with French President @EmanuelMacrone. Many good things are happening for both of our countries. Big weekend with other world leaders!" Trump posted after the meal in Biarritz, where he had just arrived for the Group of 7 (G-7) summit.

That Twitter handle, however, is for a little-followed and now dormant parody account of someone who proclaims, in a faux French flourish: "It is my English langage twiterre for directe communication withe my American and English friends."

Shortly after, the US president - one of Twitter's biggest fans and stars - corrected his message to read @EmmanuelMacron.

The mangled lunch report was one of a string of tweets sent out by the presidennt as he took a break before joining other G-7 leaders for the evening.

Among them was a repetition of his justification, first made on Friday, for an earlier comment that he is the "chosen one" to take on China in a trade war.

The suggestion that he had been handpicked by God, made outside the White House and accompanied by a theatrical glance at the heavens, was a joke, Trump repeated.

"Little did I realise that the media would claim that I had a 'Messiah complex.' They knew I was kidding, being sarcastic, and just having fun," he said in the tweet.

Trump also addressed local political issues in the US, giving no further clue to his plans for the G-7, where leaders are discussing a series of pressing global concerns.

His twitter account, followed by more than 60 million people, is closely watched around the world for breaking news, which Trump routinely announces himself rather than go through his mostly neglected press office.