President Donald Trump has announced a trade deal with Japan, under which Japanese imports would face a 15% tariff, an improvement on the 25% he threatened to impose from August 1. It was unclear what tariff rate will apply to U.S. imports to Japan.

The Guardian reports that the agreement potentially resolves weeks of fraught negotiations between the two allies which had caused economic uncertainty in Tokyo and mounting speculation over the future of prime minister Shigeru Ishiba.

“We just completed a massive Deal with Japan,” the U.S. president announced in a post online July 22, adding, “Japan will invest, at my direction, $550 billion dollars into the United States.” He also claimed that Japan would open its market to U.S. products including cars, trucks, rice and certain agricultural products – many of which had proved to be a sticking point in negotiations.

Japan is the world's fourth largest economy behind the U.S., China and Germany, and ahead of India, the U.K. and France, according to the World Bank.

“The trade deal has been received positively in Japan, but it's unlikely to be enough to help Prime Minister Shigeru Ishiba survive rising pressure to resign, in our view,” said Oxford Economics’ Director of Japan Economics Shigeto Nagai and Lead Japan Economist Norihiro Yamaguchi on July 23. “In addition, the still gloomy economic outlook and rising political uncertainty mean the BoJ will likely stay cautious on rate hikes.”

Ishiba said his country’s tariff negotiator had received the details of the deal and he would examine them before responding. “Our overarching concern is the interests of the nation,” he said.

According to BBC News, a quarter of Japan's U.S. exports are from its critical automotive sector, which accounts for almost 3% of its economy.

The Guardian said that U.S. tariffs of 50% on imports of Japanese steel and aluminum are not part of the deal, and it does not include any reference to defense spending, according to Japan’s top tariff negotiator Ryosei Akazawa.