The leaders of Canada, Mexico and the United States are expected to sign the replacement for the North American Free Trade Agreement, when they meet at the G20 summit on Friday. So what is the revised trade deal and how is it different from the NAFTA? CGTN'S Owen Fairclough explains.

DONALD TRUMP US PRESIDENT "We have successfully completed negotiations on a brand new deal to terminate and replace NAFTA. And the NAFTA trade agreements with an incredible new U.S., Mexico, Canada agreement called USMCA. Sort of just works."

The North American Free Trade Agreement transformed the trade of everything among these three countries from avocados to the zacaton root - that's used to make brushes. But Trump claimed NAFTA put Americans out of work with unfair trade practices.

"It's one of the worst deals ever made."

So how different is USMCA?

SIMON LESTER, ASSOCIATE DIRECTOR CATO INSTITUTE HERBERT A. STIEFEL CENTER FOR TRADE POLICY STUDIES "The goal of the Trump administration is to bring back auto manufacturing to the United States."

And that means increasing how much of a vehicle's content must be made in its country of origin. Under NAFTA, it was just over 60 percent - now it's 75 percent. When NAFTA took effect in January 1994, there were no ecommerce rules - Amazon didn't exist. USMCA has a whole chapter on it. And NAFTA all but fenced off Canada's dairy industry from competition. Now U.S. rivals will have greater access to their market.

But that goal of protecting American workers has already been tested - automaker GM announcing it'll cut around 14-thousand North American jobs just days before USMCA was due to be signed by the three parties. And there are likely to be other losers.

SIMON LESTER, ASSOCIATE DIRECTOR CATO INSTITUTE HERBERT A. STIEFEL CENTER FOR TRADE POLICY STUDIES "If the auto production comes back to the United States, some workers will benefit. Consumers will lose because this will make cars more expensive."

USMCA took more than a year of acrimonious negotiations and has to be ratified by each country's legislature.

OWEN FAIRCLOUGH WASHINGTON "And there's a crucial get-out provision demanded by the U.S a sunset clause that means USMCA is up for renegotiation in 16 years time. OFA CGTN Washington."