Much of the focus leading up to these talks has been on developing nations calling on richer countries to slash farm subsidies.
U.S. Trade Representative Rob Portman told reporters here Monday on the eve of the WTO ministerial, that the United States has answered that call and is waiting for others to do the same.
"The United States made a bold agricultural proposal back in October, that has yet to be matched in boldness by others, including the European union," said Rob Portman.
The United States has offered to slash export subsidies on many products by 60 percent, and eliminate them by 2010.
The European Union - whose farm subsidies are about three times higher than those of the United States - has proposed 40-percent cuts on some products, and shallower cuts on others.
EU Commissioner Peter Mandelson says he does not plan to offer any new concessions at the Hong Kong meeting. Under pressure from farmers in France, the European Union has said it is offering as much as it can.
The aim of the six-day negotiations is to come up with a plan to implement the 2001 Doha Development Agenda - which is supposed to spread the benefits of free trade broadly by giving poorer nations more access to world markets. Mr. Portman on Monday said the issue of E.U. farm subsidies is crucial to moving negotiations along.
"The gains of expanding trade will not accrue to the people of the developing world - or to Europeans for that matter - unless and until the EU commission is willing to agree to a formula that meets the Doha requirement of new trade flows [and] substantial improvement in market access," he said.
Adding to the U.S. call on Monday was Brazil, one the leading developing nations at the talks. Brazil's foreign minister told reporters that unless the European Union makes bigger concessions on agriculture, he does not believe the Doha Agenda can be fulfilled.