NEW YORK (AP) - Debate over U.S. control of core Internet systems threatens to overtake an international meeting in Brazil next week that was meant to cover topics including spam, free speech and cheaper access. The Internet Governance Forum is the result of a compromise world leaders reached at a U.N. summit in Tunisia two years ago. They agreed to let the United States remain in charge. But they established an annual forum to discuss emerging issues, including whether control of how Internet addresses are assignedand thus how people use the Internetshould remain with the U.S. government and an American nonprofit. Many countries complained U.S. dominance wasn't discussed enough during the first forum last year, in Athens. In meetings leading to the second round opening in Rio de Janeiro on Monday, China, Iran, Russia and Brazil, among others, won an opening-day panel devoted to "critical Internet resources." Some governments are seeking more concrete results, such as a chairman's statement or negotiated agreement on next steps, though U.S. and U.N. leaders cautioned that specific decisions are unlikely and even inappropriate. "If last year was viewed as a trial run, this year is in a sense a bit more important," said Michael Geist, a law professor at the University of Ottawa in Canada. "If little comes out of this, I think there will be growing concern that the IGF is little more than a talk shop and a place to meet." Some governments, particularly in developing countries, sought to strip the United States of its oversight so they could have more say over such policies as domain names in languages other than English. They failedat the U.N. World Summit on the Information Society, first in Geneva in 2003, then in Tunis in 2005and some worry that attempts to renew the debate in Rio would overshadow the rest of the forum's agenda. "What will be a shame is a repeat of Tunis pushing out these important issues," said Emily Taylor, director of legal and policy for Nominet, which operates Britain's ".uk" domain. "These were very, very hot issues during the world summit, issues over which people violently disagreed." The four-day forum, with as many as 2,000 representatives expected from government, business and the civil society, is packed with parallel sessions on network security, fighting child pornography, the cost of access, language diversity, privacy and human rights. A key theme is how to bring the Internet to the next billion people. But much of the attention is on domain names, the monikers after the "dot" that are crucial for computers to find Web sites and route e- mail. By controlling the core systems, the United States indirectly influences much of the Internet. The U.S. government, which funded much of the Internet's early development, retains veto power over the California-based nonprofit it selected in 1998 to oversee domain name policies, the Internet Corporation for Assigned Names and Numbers, or ICANN. It's not clear how strongly critics of the status quo will push for change. Many recognize that world leaders have committed to holding the forum annually for five years, but they want to see some progress this year before heading to India next year and Egypt in 2009 (Lithuania and Azerbaijan both made bids for the final round in 2010). "Let's progress slowly but that's not to say go backwards or just spin our wheels," said Hadil da Rocha Vianna, co-chairman of the forum's advisory group and director of science and technology at Brazil's foreign ministry. "So in Rio, the concrete results would be to advance in these debates, deepening themes debated in Athens." Markus Kummer, the U.N. official who heads the forum's secretariat, said he has tried to temper expectations, stressing that the Tunis document creating the forum "clearly states it's not here to make decisions." "I don't expect the meetings to change the world and come up with some real, major new decision on the re-architecture of this or that," Kummer said. "But I expect interesting meetings and interesting discussions (to improve) understanding of how the Internet works and what can be done to make it safer." Kummer said participants are free and encouraged to take what they learn to other venues, such as national legislatures or international, treaty-based bodies where change is possibleincluding the U.S. Congress and American government agencies because the United States must agree to let go. U.S. Ambassador David Gross, the State Department's coordinator for international communications and information policy, said participants range from government officials to individuals representing just themselves or millions of people. "Everyone has an equal opportunity to participate," he said, making the forum "a very poor vehicle for anyone who would seek to come to any consensus, decision-making process." Nominet's Taylor said success can be defined by the substance in dialogue and the exchange of good practicesnot necessarily binding decisions or recommendations. U.S. and ICANN officials say they welcome any discussions about their role over domain names as long as participants aren't seeking specific action, as they had at the U.N. summit. "It's fine to have the panel, and it's fine to have the discussions about it," said Theresa Swinehart, ICANN's vice president for global and strategic partnership. "But for the forum to start going into a direction that ends up coming out with recommendations, it would result in becoming four days of negotiating text. "That would defeat the purpose," she continued. "You lose the entire benefit of information-sharing. People would hold back on what they are saying."