U.S. President Donald Trump said Tuesday his administration will impose 15 percent "reciprocal" tariffs on Japanese products, 10 percentage points lower than what was previously announced, as he touted a "massive" trade deal with the Asian ally.

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."