BUSAN, South Korea (CNN) -- The leaders of 21 Asia-Pacific nations, including U.S. President George W. Bush, have begun their annual economic summit in South Korea with a call for the European Union to do more to break the impasse in talks on securing a global trade liberalization deal.The leaders are set to endorse a statement agreed upon earlier by APEC ministers that aims to foster progress in World Trade Organization talks set for next month in Hong Kong.It had been hoped an outline agreement would be reached at that meeting paving the way for a deal next year, but that is looking increasingly unlikely as differences persist on how much import tariffs should be lowered. The EU has been singled out for blame for refusing to improve its offer of tariff cuts of 38 percent on average on agricultural goods, and for the number of products it wants exempted from the cuts.South Korean Foreign Minister Ban Ki-moon told a news conference that APEC would do its best to ensure the talks succeed, but that some leaders had said the EU must take a more "proactive and flexible" position."They are basically saying that now the ball is in Europe's court," he said.The APEC draft statement acknowledged "considerable divergences" and said "a clear roadmap" must be established if the current round of talks is to succeed."We call for breaking the current impasse in agricultural negotiations, in particular in market access, which will unblock other key areas, including non-agricultural products and services," Reuters quoted the statement as saying. (Ministers adopt plan)Speaking before the official opening of the Asia-Pacific Economic Cooperation (APEC) forum, Australian Prime Minister John Howard was more direct."We are not going to get anywhere unless there is a significant matching of what the Americans have put on the table by the Europeans," he said.Mexican President Vicente Fox later said France and Spain were the most hardline opponents of further tariff reductions.Earlier this week, EU Trade Commissioner Peter Mandelson, himself having faced pressure from the French on yielding too much in the negotiations, said some within APEC seemed more interesting in "orchestrating the media" than in orchestrating a deal.He said the 25-nation EU would stick to its current offer and called for negotiating focus to switch from agriculture to goods and services.Bilateral movesWith the WTO talks deadlock seeming ever more unbreakable, many countries are turning to securing bilateral deals instead."Dealing one-on-one, it's much simpler," said Andre Lemay, spokesman for Canada's APEC delegation.Canadian Prime Minister Paul Martin meets Japanese counterpart Junichiro Koizumi on Saturday on the sidelines of the regional summit. They are expected to continue talks seen as a precursor to eventual free trade negotiations.Earlier Friday, the presidents of Chile and Mexico defended bilateral and regional free trade agreements as good for their economies, but emphasized that the ultimate goal remains a strong WTO-based multilateral trading system.China and Chile signed a free-trade agreement in Busan -- the first between the Asian giant and a Latin American country."It is essential that the leaders be able to put all of our political will and to instruct the negotiators that it is necessary to succeed," Chilean President Ricardo Lagos told a chief executives' gathering alongside the summit. Fox added that a free trade agreement for the Americas remained on track and that leaders would "keep hammering" to reach a concensus."It's not easy to reach a trade agreement, more so when you need 34 countries to agree. But we're getting closer." Varied agendaWhile APEC is designed to be primarily a forum on trade and economic matters, other issues are increasingly fighting for attention on the regional bloc's agenda. In their statement, the leaders will express strong concern about the threats of terrorism and bird flu, according to the draft seen by The Associated Press."Terrorism remains as a menacing threat to our world and we condemned terrorist acts that not only took thousands of lives but have also been aiming to destabilize the security of the region," the draft states.One member nation, Indonesia, has been the subject of a number of bombings, and officials in another, Australia, said a terror strike was recently thwarted.How to prevent the possible spread of bird flu into a human pandemic will also be a topic of discussion at the summit. In a speech Friday morning, Australia's Howard promised a "significant initiative" to help prevent the spread of the virus, also urging countries not to let national pride get in the way of combating the threat."The last thing that any nations can afford to do ... is to in any way hide or cover up the onset of the size of an outbreak," he said.According to the World Health Organization, at least 130 people in five APEC countries -- China, Indonesia, Thailand, Vietnam and Cambodia -- have been diagnosed with the H5N1 strain of the avian flu, and at least 67 have died.Also up for discussion at the summit is how to deal with North Korea's nuclear program. While North Korea is not a member of the group, five APEC countries have been involved in talks aimed at persuading Pyongyang to abandon its nuclear ambitions -- Russia, China, Japan, South Korea and the United States.The summit ends on Saturday evening.CNN Correspondents Mike Chinoy, Dana Bash and Suzanne Malveaux contributed to this report.Copyright 2005 CNN. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed. Associated Press contributed to this report.