Leaders of the Pacific Rim economies that have spearheaded the still-fragile global recovery agreed yesterday to work towards building a regional free trade zone which they say is vital for sustainable growth.

The 21-member Asia-Pacific Economic Cooperation (APEC) forum unanimouslypledged to avoid raising more trade barriers and to roll back those they may have erected in the midst of crisis.

"We reaffirm our unwavering commitment to achieving free and open trade and investment" target="_blank" title="n.投资；(时间等)投入">investment in the region," the leaders said in a declaration released after their two-day summit ended yesterday in Yokohama, Japan. "We must take steps to build a foundation for stronger, more sustainable and more balanced growth in the future."

The show of unity contrasted with the discord over currencies seen days before at the G20 summit held in South Korea last week. But worries over the frailty of the recovery seemed to lend urgency to the push for freer trade.

"The recovery is not solid, and imbalances are causing great uncertainty," Chinese President Hu Jintao told the other leaders. "The employment situation in developed countries is grim, and emerging markets face inflationary pressures and asset price bubbles."

The leaders agreed to "take concrete steps toward realizing a Free Trade Area of the Asia-Pacific," said the declaration, with Japanese Prime Minister Naoto Kan saying the rough target year was 2020.

Such a sprawling free trade zone - which would slash tariffs on imports of everything from automobile parts to food - would encompass all 21 economies, covering more than half the world's economic production and two-fifths of its trade.

This goal should build on regional groupings such as the Trans-Pacific Partnership (TPP), a United States-backed free trade agreement that nine APEC members are negotiating, and ASEAN Plus 3, which groups the 10-nation Association of Southeast Asian Nations with Japan, China and South Korea, the statement said.

Howeve, achieving such a huge free trade zone is a highly complicated endeavor given the region's diversity and vested interests opposed to opening markets.

The US, Australia, Malaysia,