US President Donald Trump’s meeting with African leaders shows a sense of urgency in competing for scarce resources with China, which recently lifted tariffs on imports from the continent.

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.

The Trump administration this week pressed five African presidents to take in migrants from other countries when they are deported by the U.S., two officials familiar with the discussions told Reuters on Thursday.