Japan's embattled prime minister Shigeru Ishiba, fresh off a crushing defeat in upper house elections over the weekend, will not be in a position of strength to negotiate a favorable trade deal with the U.S., analysts said.

Japan's ruling coalition lost control of the upper house in an election on Sunday, further weakening Prime Minister Shigeru Ishiba's grip on power even as he vowed to remain party leader, citing a looming tariff deadline with the United States.