US President Donald Trump has ordered an investigation into France's planned tax on internet services that will hit American tech giants especially hard, officials said Wednesday.

The probe into unfair trade practices could pave the way for Washington to impose punitive tariffs - something Trump has done repeatedly since taking office. And it adds yet another bone of contention in the transatlantic trade disputes that now also include trade in steel, aluminum, automobiles, aircraft and agriculture.

"The United States is very concerned that the digital services tax which is expected to pass the French Senate tomorrow unfairly targets American companies," US Trade Representative Robert Lighthizer said in a statement.

The proposed 3 percent tax on total annual revenues of companies providing services to French consumers only applies to the largest tech companies, "where US firms are global leaders," the US Trade Representative's office said.

Some internet heavyweights have taken advantage of low-tax jurisdictions in places like Ireland while paying next to nothing in other countries where they derive huge profits.

The so-called Section 301 investigation is the primary tool the Trump administration has used in the trade war with ­China to justify tariffs against what the US says are unfair trade practices.

The US Trade Representative's office will hold hearings to allow for public comment on the issue over several weeks before issuing a final report with a recommendation on any actions to take.

The US is pushing for an overarching agreement on taxation through the Group of 20 economic forum, something supported by Google. The company said last month the change would probably mean Silicon Valley tech giants would pay less in the US and more in other jurisdictions, in a departure from the long-standing practice of paying most taxes in a company's home country.