TOKYO -- Japanese Prime Minister Shinzo Abe won parliamentary approval Friday for ratification of the Trans-Pacific Partnership, despite U.S. President-elect Donald Trump's plan to withdraw from the 12-nation trade pact.

Upper house lawmakers approved the TPP on Friday, heeding Abe's calls to push ahead with it despite Trump's rejection of the free-trade initiative championed by President Barack Obama.

Abe's ruling Liberal Democratic Party has an ample majority in both houses of parliament. Ratification of needed regulatory revisions by the Cabinet is expected soon.

The market opening measures required by the trade pact are seen as a way for Abe to push through difficult reforms of the agricultural and health sectors. So far, Abe has made scant progress on a slew of changes he has proposed to help improve Japan's lagging productivity and competitiveness.

Trump has vowed to take steps to exit the pact right after he takes office.

A U.S. withdrawal would kill the trade pact unless its terms are revised. The agreement between the dozen members requires both the U.S. and Japan to join to attain the required 85 per cent of the group's total GDP since the U.S. economy accounts for 60 per cent of that total, and Japan less than 20 per cent.

After expending political capital to fight vested interests fearful of market opening and reforms likely to be required by the trade pact, Abe and other leaders in Asia have bemoaned the impending loss of the U.S. as TPP flag bearer.

"We want to carry this out and expect others will follow suit," Abe recently told a parliamentary committee.

An opposition lawmaker, Eri Tokunaga, derided Abe's insistence on going ahead with ratification as "egocentric."

"There is basically zero chance of this coming into effect since the next president, Trump, plans to leave it," Tokunaga told fellow lawmakers Friday.

Leaders in New Zealand and several other countries have said they still hope to find a way to rescue the initiative.

The outgoing Obama administration welcomed Japan's parliamentary approval of TPP.

State Department spokesman Mark Toner said that TPP was important for establishing trade rules in the Asia-Pacific and it was in everyone's interest who has signed on to it to see it come into effect. He said that regardless of what happens in the U.S., "the rest of the world is moving forward."

The TPP was meant to help give the U.S. a leading role in setting trade rules reaching beyond tariffs and other conventional trade barriers. It's possible demise could spur faster progress on another, much less discussed trade agreement called the RCEP, or Regional Comprehensive Economic Partnership. That trade grouping includes no countries from the Americas but all the big hitters in Asia: China, India, Japan, South Korea as well as Australia, New Zealand and the 10 members of the Association of Southeast Asian Nations.

Associated Press writer Matthew Pennington in Washington contributed to this report.