TOKYO, Oct 6 (Reuters) - Japanese Prime Minister Shinzo Abe welcomed the pan-Pacific agreement struck in the United States on Monday, which would liberalise trade in 40% of the world economy, though he said bringing China into the deal in future would increase its strategic significance.

"The Trans-Pacific Partnership (TPP) establishes in the Asia-Pacific a free, fair and open international economic system with countries that share the basic values of freedom, democracy, basic human rights and the rule of law," Abe told a nationally televised news conference.

"It would contribute largely to our nation's security and Asia-Pacific regional stability, and it would have significant strategic meaning if China joined the system in the future."

Twelve Pacific Rim countries reached the most ambitious trade pact in a generation, although the deal faces scepticism from U.S. lawmakers, who can vote the deal down.

If approved, the Trans-Pacific Partnership (TPP) pact would cut trade barriers and set common standards from Vietnam to Canada. It would also furnish a legacy-shaping victory for U.S. President Barack Obama and a political win for Abe, who has touted TPP as a way to boost growth in an economy checked by a shrinking population.

The agreement has also been pitched as a way to counter China's rising economic and political clout in the region.

Abe, whose ruling bloc faces a national election next July, stressed TPP would benefit Japanese consumers, workers, rural regions and companies of all sizes, not just major corporations.

"All in all, (TPP) will be a huge tailwind for Japanese companies to conduct business overseas," Abe said. "TPP definitely brings benefits to consumers and working people. The agreement would benefit the growth of Japan."

In a nod to politically powerful farmers worried they will suffer from a flood of imports after the deal, Abe said he would set up a new headquarters to craft steps to mitigate the impact.

"I am aware many people are deeply concerned," he said. The beautiful scenery of the countryside, home towns with traditional culture where people help each other, the national character we are proud of will continue to be protected. Our determination will not change at all," said the conservative leader.