Leaders of 21 Pacific Rim economies are expected to use their annual summit this week to try to revive flagging talks on global trade. On the eve of ministerial talks before the summit, the United States' top trade official called on Asian nations including China to take part "more aggressively" in efforts to forge a new international trade deal.

But it isn't clear this would be enough to break an impasse over farm subsidies that threatens to upend next month's World Trade Organization meeting.

Senior diplomats from the region are meeting in the Korean city of Busan ahead of this year's Asia-Pacific Economic Cooperation forum. They are hammering out the details of what they said will be a strongly worded statement pushing for progress when international trade talks resume in Hong Kong next month under the WTO's auspices.

U.S. Trade Representative Rob Portman said yesterday that the APEC meeting could be "very helpful" in jump-starting the trade talks, part of the so-called Doha round of trade-liberalization negotiations under the WTO. "The 21 countries [of APEC] account for half of the trade in the world, so it's a very influential group," he said. The APEC meeting, Portman said, will be "focused on breaking down" the barriers to an agreement on trade in agriculture.

During a speech at a conference in Beijing, Portman called on Asia to play a leading role in promoting free trade. "Asia, perhaps more than any part of the world, has the most to benefit and most to lose" depending on how trade-liberalization efforts proceed, the U.S. official said. He urged Asian nations to "engage more aggressively in the negotiations."

President Bush, Chinese President Hu Jintao, Japanese Prime Minister Junichiro Koizumi and other leaders will meet in Busan for two days at the end of the week. Trade will feature prominently in an agenda that will also include efforts to combat terrorism and curb the spread of bird flu.

Bush is scheduled to visit Japan before the APEC summit and China afterward.

Portman also said he will propose that key trade ministers meet in Geneva next week, after the APEC talks, in an effort to forge an agreement on cutting farm subsidies. The United States has offered to make fairly significant cuts in the money it gives farmers if Europe and Japan agree to follow suit.

But so far, Brussels has balked.

Developing nations, seeking to boost exports of agricultural goods, want the United States, European Union and other rich countries to slash subsidies to their farmers. Reluctance to do so, particularly by the European Union, has caused the talks to stall.

Australian Foreign Minister Alexander Downer, arriving in Korea for the APEC meetings, said the key to making the coming trade talks in Hong Kong a success is greater concessions by European countries on agriculture. He called on APEC to make a strong statement on the issue. "We expect a better offer from the E.U. on market access than has so far been the case," he said.

Portman urged China to encourage the European Union to reduce agricultural tariffs. "I'm concerned that unless we break the deadlock on agriculture, it will be hard to make progress in other areas," including the development agenda for non-industrialized countries, he said.

In Brussels, E.U. spokesman Peter Power said, "We have a substantial offer on the table. It goes farther than ever before in terms of cutting tariffs on agriculture."

The December trade talks in Hong Kong were dealt a blow earlier this month in Argentina at a summit of heads of state from Western Hemisphere nations. Washington suffered an embarrassing defeat at that meeting when its efforts to restart talks on a pan-American free-trade agreement were rebuffed.

Fairclough reported from Seoul, and Hiebert reported from Beijing. Scott Miller in Brussels contributed to this report.

South Korean protesters rally against President Bush and the Asia-Pacific Economic Cooperation summit in Busan, South Korea.

Hyun Jae-hyun, chairman of the APEC Business Advisory Council, addresses delegates yesterday in South Korea.

U.S. Trade Representative Rob Portman.