US-China dispute casts shadow as world leaders gather in Argentina

One bright spot in Buenos Aires on Friday before the summit opened was the signing of a revised U.S.-Mexico-Canada trade pact to replace the North American Free Trade Agreement.

Signing the agreement alongside Canadian Prime Minister Justin Trudeau and Mexican President Enrique Pena Nieto, Trump said he looked forward to working with the U.S. Congress to complete the terms of the deal and did not anticipate problems in passing it.

The three countries agreed a deal in principle to govern their trillion dollars of mutual trade after a year and a half of contentious talks concluded with a late-night bargain just an hour before a deadline on Sept. 30.

However, Trudeau took advantage of the signing ceremony to say the partners needed to keep working to lift tariffs on steel and aluminum.