President Donald Trump welcomed leaders of five African nations, hailing the continent’s economic potential as his administration seeks to expand US access to critical minerals and other natural resources.

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 Trump is hosting 5 African leaders in Washington this week — a selective summit that's raising eyebrows over who was invited, what's on the table, and what it signals about U.S. rivalry with China and BRICS in Africa.