BUFFALO, NY - It's a move the President says is intended to help even the trade imbalance with China.

But Canadian officials are now warning of the possibility of retaliation, if President Trump does not create a “carve out” for Canada when it comes to his proposal to heavily tax imported steel.

This is raising concern among some U.S. officials, including New York's Senior Senator, Charles Schumer, who spoke about the issue with reporters in Buffalo Monday.

"I totally approve of going after China,” said Schumer, a democrat. “China has been the worst trading partner we have they are rapacious...It’s time we got tough with China."

However, Schumer also expressed concern about the impact such a move would have on a friendlier trading partner in Canada.

“If you don't do it smart, it may hurt other places like Canada," Schumer said.

Among nations, Canada represents the United States’ second largest trading partner, and the largest market for U.S. exports.

In addition, it is the No. 1 supplier of both steel and aluminum to the U.S. and moreover, is just across the Peace Bridge from Buffalo, over which billions of dollars of goods flow.

As Canadian leaders try to negotiate an exemption on their steel and aluminum for export to the U.S., President Trump on Monday said there would be no exemption, unless Canada and Mexico concede to his long sought desire to renegotiate the North American Free Trade Agreement (NAFTA).

NAFTA is something Schumer voted against when enacted, and something he accused Canada of violating less than a year ago when it sought to limit the importation of ultra-filtered milk, which he said would hurt New York dairy farmers

"That was [Canada] specifically excluding a product with no reason to exclude it. China is dumping steel and aluminum, but we have to see what if what the President is proposing will actually stop that without causing damage in other places."

Leaders of the President’s own party are expressing concern as well.

“We are extremely worried about the consequences of a trade war and are urging the White House to not advance with this plan,” said a spokesperson for House Speaker Paul Ryan. “The new tax reform law has boosted the economy and we certainly don’t want to jeopardize those gains.”