President Donald Trump said Friday that he will increase the tariffs charged on cars and trucks from the European Union next week to 25%, a move that could jolt the world economy at a fragile moment.

Trump said in the post that the EU “is not complying with our fully agreed to Trade Deal", though he did not flesh out his objections in the post.

A trade deal, which was struck last summer, had capped the US tariff on EU autos and parts at 15 percent, which is lower than the 25-percent duty that Trump imposed on many other trading partners.