U.S. policies which act as a barrier to Canadian businesses bidding on government projects are about to get more stringent.

U.S. President Donald Trump signed an executive order Monday demanding that 75 per cent of the value of any components in “Made in America” products must to be sourced in the U.S. That’s an increase from 50 per cent previously.

And, in a fresh blow to Canada’s steel industry, he has demanded that 95 per cent of steel and iron used in any public contract must be from the U.S.

Tariffs of 25 per cent on Canadian steel and 10 per cent on Canadian aluminum exported to the U.S. were lifted in May, months after a new NAFTA deal was signed.

Canadian companies are already restricted in bidding on road, bridge and other public projects from the U.S. government or any state with Buy America restrictions.

The new rules limiting public projects to using 95 per cent U.S. steel will further limit opportunities to win business.

The president signed the order during an annual White House “Made in America” showcase. Manufacturers from all 50 states were represented.

Trump says the administration is “heeding the wisdom” of the nation’s founders by “restoring our economic independence and reawakening our industrial might.”

Canada’s premiers have called on Prime Minister Justin Trudeau to gain an exemption from Buy America provisions.