President Donald Trump has announced he plans to increase a tariff on cars and trucks imported from the European Union effective next week, a move that could jolt the world economy at a fragile moment. “I am pleased to announce that, based on the fact the European Union is not complying with our fully agreed to trade deal, next week I will be increasing tariffs charged to the European Union for cars and trucks coming into the United States. The tariff will be increased to 25%,” he wrote Friday. “It is fully understood and agreed that, if they produce cars and trucks in U.S.A. plants, there will be NO TARIFF.” Trump did not elaborate on his specific grievances over the EU and their supposed noncompliance with the trade deal. It comes despite an agreement reached last July between Trump and European Commission President Ursula von der Leyen, which established a 15% tariff on the majority of goods. President of the European Commission Ursula von der Leyen shakes hands with U.S.…