TOKYO (AP) -- Japan's trade minister said Tuesday that he has failed to win assurances from U.S. officials that the key U.S. ally will be exempt from tariffs, some of which effect on Wednesday.

Yoji Muto was in Washington for last ditch negotiations over the tariffs on a range of Japanese exports including cars, steel and aluminum.

Muto said Tuesday that Japan, which contributes to the U.S. economy by heavily investing and creating jobs in the United States, "should not be subject to" 25% tariffs on steel, aluminum and auto exports to America.

His meetings with U.S. Commerce Secretary Howard Lutnick, U.S. Trade Representative Jamieson Greer and White House economic advisor Kevin Hassett on Monday came just two days before the steel and aluminum tariffs are due to take effect. President Donald Trump has also said a possible 25% tariff on imported foreign autos could take effect in early April.

Muto said the U.S. officials acknowledged Japanese contributions and agreed to continue talks, but did not approve his request for Japan's exemption from the steep import duties.

"We did not receive a response that Japan will be exempt," Muto told reporters. "We must continue to assert our position."

Japan depends heavily on exports and the auto tariffs would hurt, because vehicles are its biggest export and the United States is their top destination.

Trump also has criticized Japan's contributions to the two countries' mutual defense arrangements, adding to tensions with Tokyo.

Muto said the two sides agreed to keep discussing to find ways to establish a "win-win" relationship that would serve national interests of both countries.

The two sides also discussed energy cooperation, including joint development of the liquefied natural gas in Alaska, which Trump and Prime Minister Shigeru Ishiba agreed on during Ishiba's visit to the White House in February.