Sen. Elizabeth Warren, D-Mass., who is considered a possible Democratic contender for the 2020 White House race, is coming out against President Donald Trump's renegotiated trade deal with Mexico and Canada, just as the president and his counterparts are set to sign it at the G-20 summit.

The deal, called the United States-Mexico-Canada Agreement, or USMCA, is intended to replace the 24-year-old North American Free Trade Agreement, which Trump repeatedly assailed on the campaign trail and in the Oval Office.

In remarks prepared for a speech Thursday afternoon, Warren said as it's currently written, "Trump's deal won't stop the serious and ongoing harm NAFTA causes for American workers. It won't stop outsourcing, it won't raise wages, and it won't create jobs. It's NAFTA 2.0."

The U.S., Canada and Mexico are expected to formally sign the agreement Friday in Buenos Aires. But the deal must still be approved by Mexican and Canadian legislatures and Congress.

Warren sites items Democrats have long complained about: labor standards, lower environmental standards and rules protecting pharmaceutical companies patents.

"The new rules will make it harder to bring down drug prices for seniors and anyone else who needs access to life-saving medicine," said Warren.

The agreement is also facing opposition from GOP lawmakers. Sen. Pat Toomey, R-Pa., laid out his objections to the deal, including the sunset provisions, which require the deal be reviewed every six years and renewed every 16 years, rules of origin with wage requirements and weakened investor protections. He's also highly critical that the tariffs on steel and aluminum were not removed in the deal. "I would be a 'no' in its current form," said Toomey. He was pushing for passage during the lame-duck session, but it's more likely this will come in the new Congress.

In a tweet, Sen. Marco Rubio said he spoke with U.S. Trade Representative Robert Lighthizer about how bad the deal is for seasonal growers, "It will allow Mexico to continue unfair practices that will literally put many Florida farmers out of business."

The details of the USMCA are still being negotiated and there has yet to be a resolution on the steel and aluminum tariffs that Mexico and Canada have retaliated against. But that could be a moot issue if the U.S. can reach an agreement with China to suspend tariffs.

In addition, Democrats are urging Trump to maintain his tough stance on China. "We have seen disturbing reports that you may be considering backing down on further action against China in order to reach an agreement at the G-20," wrote Sen. Chuck Schumer, D-N.Y., along with Sens. Ron Wyden, D-Ore., and Sherrod Brown, D-Ohio, in a letter to Trump. "We urge you to stand firm against China if meaningful concessions are not made."