The U.S.-Mexico-Canada (AKA the New NAFTA) Trade Deal: Withdrawing from the New NAFTA
The original NAFTA withdrawal provision, Article 2205, said this:
A Party may withdraw from this Agreement six months after it provides written notice of withdrawal to the other Parties. If a Party withdraws, the Agreement shall remain in force for the remaining Parties.
The new NAFTA withdrawal provision, Article 34.