Certainly doesn't help that he fired the US's pandemic response team a few years ago (that pesky "deep state" he's been ranting about). The rest of the world has their own responsibility to some extent but the US usually takes point on these kind of things.
https://www.snopes.com/fact-check/trump-fire-pandemic-team/
He's also had the CDC sandbagging testing for it. He's been claiming coronavirus is a liberal hoax for weeks now, and anyone who contradicts him gets fired.
One of the side effects of that has been the CDC refusing to approve states that developed their own testing (as they are required to get CDC approval). Because they don't want to be seen as arguing that COVID is not a liberal hoax.