TOKYO (AP) — Prime Minister Shigeru Ishiba on Wednesday vowed to remain in power to oversee the implementation of a new Japan-U.S. tariff agreement, despite media speculation and growing calls for him to resign after a historic defeat of his governing party.

A day after the United States reached a trade deal that imposes a 15 percent tariff on imports from Japan, President Donald Trump declared that U.S. business would “BOOM.” But early reads from auto analysts paint a murkier picture — if anything, some experts say, Japanese companies may benefit more than their rivals for now.

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