Maehara also said the ruling Democratic Party of Japan should include its stance on the pact, called the Trans-Pacific Partnership (TPP), in its policy platform for the next general election, expected within months.
"I think Japan should push for free trade and join TPP talks," Maehara told reporters, adding that he was presenting his views as a party member rather than a cabinet minister.
He said Japan should also seek free trade deals with China and South Korea as well as an economic partnership agreement with the European Union.
Exporters have been lobbying for membership in the TPP and other free trade pacts, concerned that South Korea was gaining an advantage in securing trade deals with major partners such as the United States and the European Union.
But the pact is fiercely opposed by Japan's protected farming sector, which wields considerable political influence.
Prime Minister Yoshihiko Noda expressed Japan's interest in joining talks on the TPP a year ago, but has since remained non-committal in the face of opposition within his party and the public at large.
Maehara, however, suggested that rather than side-stepping the issue, the ruling party should tackle it head-on, making free trade part of its election manifesto.
General elections are not due until next August, but could come as soon as next month.
Noda promised in August to hold an early election to break a
stalemate in parliament and push through a tax increase plan. But he has since declined to commit himself to a date.
A fellow cabinet member, Trade Minister Yukio Edano, said the government should decide the fate of TPP talks before going to the polls, which public opinion surveys suggest the ruling party will lose badly.
"The current government should make a decision on joining TPP talks as soon as possible," Edano told a regular briefing. "The decision should be made before the next election."
The Yomiuri newspaper, citing aides and lawmakers, said Noda might declare Japan's readiness to join the pact after the passage of a budget deficit financing bill expected this month.
However, chief government spokesman Osamu Fujimura denied that a decision on the timing of an announcement had been made.
The nine current TPP countries - the United States, Australia, New Zealand, Vietnam, Malaysia, Singapore, Brunei, Chile and Peru - recently welcomed Canada and Mexico into the negotiations, highlighting the uncertainty over whether Japan will actually join the talks or not. (Reuters)