BRUSSELS (AP) – The European Union says that if U.S. President Donald Trump initiates unfair trade measures against the 28-nation bloc, it would stand ready “to react swiftly and appropriately.”

In a weekend interview, Trump said he was annoyed with EU trade policy since he claims the U.S. cannot sufficiently export to the EU. He said his problems with the EU “may morph into something very big” from a trade standpoint.

EU spokesman Margaritis Schinas retorted Monday that “while trade has to be open and fair it also has to be rules-based.”

Schinas said: “The EU stands ready to react swiftly and appropriately in case our exports are affected by any restrictive trade measure from the United States.”