The Diet on Friday enacted legislation necessary for the completion of domestic procedures ahead of the ratification of the revised Trans-Pacific Partnership free trade pact.
The passage of the bill through the House of Councillors has set the stage for Japan to finalize its domestic arrangements in early July, after it finishes revising relevant government ordinances.
The Diet has already agreed to ratify the TPP, which the Cabinet Office says will potentially give the nation's real gross domestic product a boost of 1.5 percent.
The new law includes support for livestock farmers, who will be exposed to foreign competition, and extends intellectual property rights in line with the trade pact.
The government hopes to finish its domestic processes and pave the way for the TPP to come into force possibly this year amid growing concerns about U.S. President Donald Trump's protectionist policies and fears of trade friction.
After the United States withdrew from the free trade framework the remaining 11 members in March signed the current TPP, which is formally called the Comprehensive and Progressive Agreement for Trans-Pacific Partnership.
The TPP will enable consumers to buy cheaper goods, but farmers have expressed concern that they could be hit by increased imports of agricultural produce.
The pact will take effect after at least six member countries ratify it. Mexico has already completed its domestic procedures.
The TPP 11 members are Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam. Thailand has expressed a willingness to join the pact.