The United States-Mexico-Canada Agreement (USMCA) includes provisions forbidding member states from participating in currency manipulation. Here’s the relevant section, Article 33.4 of Chapter 33 of the USMCA:
Each Party should:
(a) achieve and maintain a market-determined exchange rate regime;
(b) refrain from competitive devaluation, including through intervention in the foreign exchange market; and
(c) strengthen underlying economic fundamentals, which reinforces the conditions for macroeconomic and exchange rate stability.
Furthermore, the agreement includes a requirement to inform the other countries if it has undertaken an action with regard to the other country’s currency.