Manitoba Gary Doer joins other Prairie premiers in lobbying against the proposed 'Buy American' provisions of the U.S. economic stimulus package. (CBC)

Manitoba Premier Gary Doer and Saskatchewan Premier Brad Wall were travelling to the United States Monday to lobby against protectionist measures in U.S. President Barack Obama's economic stimulus bill.

Doer and Wall planned to stop first in Chicago before travelling to Houston, where they were to meet up with Alberta Premier Ed Stelmach.

The $825-billion-US stimulus package was passed by the House of Representatives in January. It includes a "Buy American" provision that requires public works projects to use only U.S.-made iron and steel.

That could mean bad news for Canadian industries, including steel producers in Selkirk, Man. Doer said putting up trade walls is not the solution.

"It's totally offside with NAFTA, and it's inconsistent with American best interests and Canadian best interests," said Doer. "It's in their best interest to trade."

The U.S. Senate began debating the stimulus bill on Monday and is considering even broader "Buy American" provisions designed to ensure that money stays in the United States.

Canada and other countries fear "Buy American" barriers could trigger a cycle of retaliation that would strangle world trade and undermine efforts to end the global economic crisis.

Over the weekend, Obama suggested he has heard the concerns of the NAFTA partners and would review the provision.

But Canada's international trade minister, Stockwell Day, said Canadians have been given no guarantees the provision will be dropped.

Canada, the top trading partner for the United States, exports billions of dollars worth of steel and iron to its southern neighbour annually.

Doer said restricting free trade could actually deepen the U.S.-led recession.

"People might think in the United States that putting protectionist measures in will in fact protect jobs in the U.S.," he said. "But we argue it will have the opposite affect, that more jobs will be lost in the U.S. as walls go up."