The United States on Thursday said China had submitted an improved offer to join a WTO pact that allows members better access to lucrative government contracts.

"China submitted its revised offer last week. We are still analyzing it but we recognize that it includes significant improvements over its initial offer that was submitted at the end of 2007," said deputy US trade representative Demetrios Marantis.

Marantis said the new offer could be "a solid step toward ensuring China's huge government procurement market is open to US companies."

Last month US lawmakers proposed a ban on the US government buying Chinese-made goods or services until Beijing signs the WTO's agreement on government procurement, or GPA.

The lawmakers, three Democrats and Republican Senator Lindsey Graham, complained that US firms cannot compete in China's government procurement market, estimated at $500 billion, while the US government buys Chinese tires, ammunition, office equipment, and other items.

"After we complete our analysis, including consulting with domestic stakeholders, we will work with China and other GPA members to ensure China terms of accession are comprehensive and comparable to that of other GPA parties," said Marantis.

The pact demands that countries do not discriminate against foreign bidders in non-defense contracts.