The United States on Friday hailed Japan's plan to join the talks for the Trans-Pacific Partnership free-trade zone.
"The United States welcomes Prime Minister (Shinzo) Abe's important announcement formally expressing Japan's interest in joining the Trans-Pacific Partnership negotiations," said Acting US Trade Representative Demetrios Marantis.
"Since early last year, the United States has been engaged with Japan in bilateral TPP consultations on issues of concern with respect to the automotive and insurance sectors and other non-tariff measures," he said in a statement.
"We look forward to continuing these consultations with Japan as the 11 TPP countries consider Japan's candidacy for this vital initiative in the Asia-Pacific region."
But the US Alliance for American Manufacturing, which is backed by the US auto industry, was critical of the idea of Japan joining the talks.
"We should welcome and encourage Japan's interest in freer trade, but let's not roll out the red carpet for their inclusion in the TPP," said AAM president Scott Paul.
"Japan's closed market, currency manipulation, and many other concerns stand in the way. It's not worth sacrificing American jobs and American manufacturing to secure a TPP agreement at any cost."