The U.S.-sponsored meeting of major emitting countries is aimed at supporting and accelerating the U.N. process on climate change, Secretary of State Condoleezza Rice insisted on Thursday.

Skeptics, including dozens of protesters gathered outside the U.S. conference, have expressed concern the climate meeting might be an attempt to circumvent the United Nations process.

But in opening a two-day session at the State Department, Rice said the United States "supports the goals" of a U.N. summit on climate earlier this week "and we want this year's U.N. climate change conference in Indonesia to succeed."

The United Nations meeting on Monday drew more than 80 heads of state and government to focus on the problem of global warming.

The Washington meeting drew ministers from the world's biggest greenhouse gas polluters -- including the United States and China. It was called by President George W. Bush, whose administration has been criticized for refusing to adopt mandatory limits for climate-warming emissions. The White House favors "aspirational" targets.

By most counts, the United States is the No. 1 emitter of greenhouse gases, notably carbon dioxide produced by coal-fired power plants and petroleum-fueled vehicles. But at least one study this year indicated that fast-developing China is now in the lead.

Other participants are the European Union, France, Germany, Italy, the United Kingdom, Japan, Canada, India, Brazil, South Korea, Mexico, Russia, Australia, Indonesia and South Africa.

About 60 protesters, many of them from Greenpeace and other environmental groups, chanted anti-Bush administration slogans and held up placards outside the State Department while diplomatic security formed a line preventing them from getting into the building.

(Additional reporting by Caren Bohan and Sue Pleming)