Wine connoisseurs talk about needing "a nose" to assess the quality of a vintage. The US President Donald Trump just uses his eyes.

A famous teetotaler, Trump raised eyebrows on Friday with his insistence that he likes US wine more than the French version. How could he know?

"I've always said American wine is better than French wine!" the president tweeted, while warning that he may raise import tariffs on France's iconic drink due to a dispute over French taxes targeting US tech companies like Google, Apple, Facebook and Amazon.

Later in the Oval Office, he explained his technique.

"I don't drink wine. I just like the way they look."

Trump, 73, has repeatedly said he has never had a drink over the course of his life - meaning it's unclear how he could have formed an opinion on the supposed superiority of American wines over their French counterparts, the UK's media Independent said in a report on July 27.

AFP