The Trump administration formally gave Congress a list of its proposed changes to trade policy, requests that will put the U.S.-Mexico-Canada Agreement on trade into effect.

The list is the first step in getting Congress to approve the trade deal that would replace the 1993 North American Free Trade Agreement. Replacing NAFTA has been a major goal for President Trump.

"I look forward to working with Congress to implement this important agreement," U.S. Trade Representative Robert Lighthizer told Senate Finance Committee Chairman Chuck Grassley, R-Iowa., in a letter Tuesday.

The list says the deal will change the "rules of origin" for when autos and auto parts can be imported duty-free. The letter doesn't list the specific changes, but the White House has said the deal would raise the level to 75 percent, up from 62.5 percent under current rules. The letter also states the deal will set tariff rate quotas for agricultural products from Canada, including dairy, sugar, and peanuts, and include language transitioning the U.S. out of NAFTA, among other changes.

Grassley was cautious regarding the administration's proposals. "This is an important step required under U.S. law to implement the new trade deal with Mexico and Canada. Congress has to carefully consider the agreement and work out the details before it can be ratified," he said in a statement.

The deal is expected to face opposition from both parties in Congress. House Speaker Nancy Pelosi, D-Calif., has been noncommittal about bringing it up, saying Mexico had to first reform its labor laws to make the deal's provisions acceptable.

Mexico has passed only limited reforms, which are seen as inadequate by some Democrats. Some Republicans are critical as well. Sen. Marco Rubio, R-Fla., has said it would harm his state's agricultural industry and Sen. Pat Toomey, R-Pa., has called for more free-market reforms.

Lighthizer told Politico Tuesday the White House was expecting resistance from some lawmakers. "Everything will be controversial ... because everything is with us, right?"