Donald Trump says he is not a "big fan" of tech companies. (File)

US President Donald Trump on Friday reiterated criticism of a French proposal to levy a tax aimed at big US technology companies and threatened again to retaliate by taxing French wine.

Speaking to reporters at the White House before leaving for a Group of Seven summit in France, Trump said he is not a "big fan" of tech companies but "those are great American companies and frankly I don't want France going out and taxing our companies."

"And if they do that ... we'll be taxing their wine like they've never seen before," he said.