Prime Minister Yoshihiko Noda's announcement that Japan will join multilateral talks on the Trans-Pacific Partnership free-trade framework was welcomed by leaders of countries already involved in the negotiations when they gathered over the weekend for their regional economic summit in Hawaii.

But while Noda may have felt his efforts to reach the controversial decision paid off to some extent, it is unclear how involved Japan can get in the rule-making process for the U.S.-backed framework given the nine countries so far involved in the talks have already reached a broad outline. Strong opposition at home also makes prospects unclear.

Despite a series of campaigns against the TPP and opposition even from some of his own lawmakers, Noda said Friday that Japan will begin consultations with related countries as a step toward joining negotiations on the pact.