SASKATOON - Prime Minister Stephen Harper calls the latest attempt by the United States to implement Buy American restrictions a "regrettable development" that will weigh down economic growth in North America.

A new job-creation package from President Barack Obama would resurrect protectionist measures that would require work on public infrastructure be done with U.S.-made materials. Harper said he likes the president's broader plan, but not the Buy American element.

"We're obviously very concerned that once again they're looking at stimulus spending that has protectionist elements," Harper said Friday at a news conference in Saskatoon.

"And, as the minister of trade has said, you know at the state we're in, in the economy globally and here in North America, these things are not positive developments in terms of moving our economies forward."

Earlier in the week, Trade Minister Ed Fast said protectionist barriers between the two countries make no sense given the close integration of the North American economy. He said they would cost both countries jobs and efficiencies.

Ottawa fought for more than a year to secure a Canada exemption to the Buy American provisions in a US$900-billion stimulus package in 2009. The compromise gave a waiver to Canadian suppliers in exchange for a commitment from provinces that they would not discriminate against U.S. contractors.

But that deal doesn't apply to the second round of stimulus being proposed by Obama.

Harper said Ottawa will press its case again.

"We dealt with this very productively with the Obama administration the last time. We have an ongoing dialogue on these measures and we obviously will be making our views known," he said.

"But I think it's a very regrettable development and we will be expressing that regret and the desire to move forward together and positively at the highest levels of U.S. government."

The issues in the current bill are almost identical to what Canadian exporters faced two years ago. It contains a directive that none of the government money may be used for "the construction, alteration, maintenance or repair of a public building or public work unless all of the iron, steel and manufactured goods used in the project are produced in the United States."

The bill does state the package must be consistent with U.S. obligations under international agreements -- an exemption that was also contained in the original stimulus law two years ago.

And it would allow foreign participation in cases where excluding foreigners raised project costs by more than 25 per cent.

Fast said he wrote to U.S. Trade Representative Ron Kirk to trigger the expedited consultation mechanism which exempted Canada from the earlier Buy American provisions.

Fast said he also spoke Friday to Kirk and reiterated Canada's concerns and requests.