Japan says it will participate in talks to join a U.S.-backed Pacific Rim free trade zone, a decision opposed by Japanese farmers who say the move will hurt them.

Japanese Prime Minister Yoshihiko Noda says he will hold talks about joining the proposed Trans-Pacific Partnership with leaders at an Asia Pacific Economic Cooperation summit that begins Saturday in Hawaii.

He says having a role in the talks is in Japan’s national interest. He said his country will defend what it must protect and win what it needs to gain.

The prime minister was expected to announce the move on Thursday, but intense debate within his ruling Liberal Democratic Party delayed the decision.

Big Japanese exporters say joining the zone will put them on a more equal footing with some of their rivals. But heavily protected Japanese farmers say their livelihoods will be threatened by cheaper, imported agricultural products.

Until now, Trans-Pacific Partnership negotiations have involved the U.S., Australia, Brunei, Chile, Malaysia, New Zealand, Peru, Singapore and Vietnam.