BUENOS AIRES, Argentina -- Canada will sign the United States-Mexico-Canada Agreement today in Buenos Aires, on the sidelines of the high-profile G20 summit.

Prime Minister Justin Trudeau will join U.S. President Donald Trump and outgoing Mexican President Enrique Pena Nieto to formally sign the trade agreement early this morning.

Today marks an important deadline for the revamped version of NAFTA.

A new Mexican president takes over on Saturday, who might not honour the tentative deal struck by his predecessor.

The signing of the trade agreement is largely ceremonial, because it will still need to be ratified by all three countries before it can formally take effect.

U.S. lawmakers have already indicated they don't expect to tackle the USMCA until after the new Congress is sworn in early next year.