The Trump administration on Thursday notified Congress that it plans to renegotiate the North American Free Trade Agreement, the three-member deal with Mexico and Canada that President Donald Trump has repeatedly attacked.

The United States can start renegotiating the agreement 90 days from the notification to Congress. A letter from U.S. Trade Representative Robert Lighthizer to congressional leaders says the administration wants NAFTA to be "modernized."

The United States seeks to support higher-paying jobs in the United States and to grow the U.S. economy by improving U.S. opportunities under NAFTA ... In particular, we note that NAFTA was negotiated 25 years ago, and while our economy and businesses have changed considerably over that period, NAFTA has not. Many chapters are outdated and do not reflect modern standards. For example, digital trade was in its infancy when NAFTA was enacted. In addition, and consistent with the negotiating objectives in the Trade Priorities and Accountability Act, our aim is that NAFTA be modernized to include new provisions to address intellectual property rights, regulatory practices, state-owned enterprises, services, customs procedures, sanitary and phytosanitary measures, labor, environment, and small and medium enterprises.

In his campaign, Trump railed against NAFTA, saying that the deal has sapped manufacturing jobs from the U.S. He has kept up that rhetoric since he took office, and his administration has taken actions against what it deems unfair Canadian practices.

The president even threatened to pull out of NAFTA entirely, but reportedly decided not to after phone calls with the leaders of Mexico and Canada.

Here's the full letter posted by the Office of the U.S. Trade Representative: