The U.S. dollar strengthened against the Swiss franc and euro but weakened versus the yen on Wednesday as positive sentiment from a new U.S. trade deal was offset by political uncertainty surrounding Japanese Prime Minister Shigeru Ishiba's future.

Asian shares have rallied, with Tokyo's benchmark Nikkei 225 index up more than 3% after Japan and the U.S. announced a deal on President Donald Trump's tariffs.

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."