A powerful US manufacturing group launched a campaign Monday to lock Chinese suppliers out of large US infrastructure projects, saying Beijing does not reciprocate market access.

The Alliance for American Manufacturing (AAM) kicked off the campaign by blasting California's reliance on China to supply thousands of tons of steel for the $7.2 billion San Francisco-Oakland Bay Bridge eastern span, which is nearing completion.

AAM unveiled huge billboards near the two ends of the span, reading on a background of the China's red flag, "The Bay Bridge: 100 Percent Chinese Steel", and a link to the group's "Should Be Made In America" campaign.

"It is a symbol of what not to do... as our country begins to invest infrastructure," said executive director Scott Paul.

"We need to make sure that our federal laws and our state laws give an appropriate preference to domestic firms for large scale infrastructure projects."

By singling out the Bay Bridge project, which was contracted out in 2006, he said AAM is aiming to make officials and the public know "what is at stake."

"There is a capacity to do this work in the United States," he told AFP.

The campaign was launched as Congress considers a $109 billion, two-year transportation spending bill, which the government hopes will give a boost to the economy and generate more jobs.

It also comes as both Democratic President Barack Obama and the Republicans vying to challenge him in the November presidential election both spotlight China, and its huge trade surplus with the US, as the source of many of the country's economic woes.

In February President Barack Obama took direct aim at China's huge trade surplus with the United States when he ordered the creation of the Interagency Trade Enforcement Center to expedite unfair trade complaints from US business.

The administration has also boosted its actions, in recent weeks hitting or threatening to hit Chinese exports of solar cells, steel wire, chemicals used for making paper, and even kitchen sinks with anti-dumping and counter-subsidy duties.

Paul said that because China had not signed on to the Government Procurement Agreement (GPA) of the World Trade Organization, the US was free to cut Chinese suppliers out of infrastructure projects.

"With respect to China we would be perfectly within out rights to completely close our markets to Chinese bids."

The campaign is not aimed at locking all foreign content out of US projects, Paul said.

"We do have reciprocity with a lot of countries, we have open procurement," he said.

"We certainly don't have it with China and some other countries which have not signed onto the GPA."

The campaign plans to put a spotlight on a new project each week that AAM says unnecessarily used foreign -- mainly Chinese -- content.

The aim, Paul said, was to force open China's procurement policies for its own projects while "ensuring that there is less Chinese steel in American projects."