In a letter released on his social media platform, Donald Trump told Canadian Prime Minister Mark Carney the new rate would go into effect on August 1 and would go up if Canada retaliated.

President Donald Trump met the presidents of five African nations -- Senegal, Liberia, Guinea-Bissau, Mauritania and Gabon -- in what the White House describes as a push to deepen trade, including precious medals.

The administration is aiming to strike deals to expand the United States’ access to critical minerals and to counter China’s rising influence in Africa.