Canada has agreed to join a new trade deal with the United States and Mexico that will replace the existing North American Free Trade Agreement (Nafta).

The new deal will be called the United States-Mexico-Canada Agreement (USMCA) and is worth an estimated $1.2 trillion.

Until last week the negotiations had been at an impasse, with only the US and Mexico having come to an agreement. The US had told Canada it was ready to move forward with a bilateral deal and president Donald Trump criticized its North American neighbour for slowing the pace of the discussions.

However, the US then told Canada it would be willing to make some concessions, according to sources close to the White House, leading to a weekend of hammering out a revised agreement.

Now, a deal has finally been reached that will create what Mr Trump called a "truly historic" trade agreement and the "most important" ever agreed by the US.

Canadian prime minister Justin Trudeau has said USMCA will be "profoundly beneficial" to Canadians, although he conceded that the nation had been required to make compromises in order to see the deal go through.