A multilateral investment treaty between Mexico, Canada and the US. The agreement came into force in 1994 and created a free-trade zone between the countries. Chapter 11 of NAFTA contains provisions protecting foreign investors in the three countries, including requirements such as:

Chapter 11 also provides for investor or state disputes to be referred to arbitration pursuant to the International Centre for Settlement of Investment Disputes (ICSID) or UNCITRAL rules.

On 1 July 2020, the US-Mexico-Canada Agreement (USMCA) entered into force. The USMCA replaces the North American Free Trade Agreement (NAFTA), which was devised following NAFTA renegotiations in 2017 under the Trump administration (see Legal update, Trump administration launches NAFTA renegotiations). NAFTA will remain in effect for three years from the date the USMCA comes into force.

Under the USMCA, investor-state dispute settlement (ISDS) will only exist for certain investment disputes between investors of US and Mexico and those two nations. There will be no ISDS between Canada and US or between Canada and Mexico (see Legal update, ISDS provisions radically amended in new NAFTA agreement renamed USMCA).