O negative is a very rare blood group globally, I should imaging that most countries are in short supply, some more than others.
Since type O blood is that which can be used for anyone, it is almost always in short supply at hospitals. If you have it, you should think of donating. About 42% of the global population has type O+ blood but just 3% have type O-.
https://www.worldatlas.com/articles/what-are-the-different-blood-types.html