The dollar struggled on Wednesday, while the yen was choppy after U.S. President Donald Trump announced a trade deal with Japan, bolstering optimism for more agreements ahead of an impending tariff deadline.

Trump said the U.S. will impose a 15% tariff on Japanese imports under the agreement, which he hailed as "maybe the largest deal in history."

The agreement will impose tariffs of 15 percent on Japanese goods, down from a threatened 25 percent. Trump said Japan would also invest $550 billion in the U.S.