The proposals made a week ago by the chief negotiator guiding the WTO's farm talks marked an improvement, but there were still significant shortcomings, especially on reducing import duties, said US agriculture negotiator Joseph Glauber.

"A lot of work has been done in the export competition and domestic support, in contrast with market access... a significant portion on market access is just lacking," Glauber told journalists.

He was speaking on the sidelines of the first meeting of the WTO's 150 members to discuss the proposals drafted by the head of the WTO's agriculture group, New Zealand ambassador Crawford Falconer.

Washington is trying to balance any concessions it makes in reducing the amount of support paid out to US farmers with cheaper access to agricultural export markets.

The proposed modalities on agriculture effectively suggested that Washington should rein in overall trade-distorting support for US farmers to between 12.8 billion and 16.2 billion dollars a year.

Some types of domestic subsidies do not affect international trade, according to the WTO.

Glauber said that Washington was ready to make an effort on domestic support, but he said a figure in the low teens was "out of the question".

The draft modalities on two of the three pillars in the talks, agricultural and industrial trade, released on July 14 are aimed at reviving the stuttering six year-old effort to reduce global trade barriers.

The WTO's 150 members are due to give their first reactions to the other proposals, Non Agricultural Market Access or industrial goods, in another meeting in Geneva on Wednesday.