Microsoft cofounder Bill Gates slammed the US government's response to the COVID-19 pandemic on Wednesday.
The US had attacked its scientific experts, fallen behind other countries on testing, and failed to get its citizens to wear masks, he said.
Many countries have "done very, very well" on getting people to change their behaviour â€" but not the US, he said.
Testing results take longer to come back in the US than in other countries, Gates said, which he described as "mind-blowing."
"Our response in most respects has not been very good. And we would have expected it to be good," the billionaire said in a CNBC interview on Wednesday.
"Mask compliance in the United States is quite poor. And yet the cost of the mask and the productivity lost from [not wearing] the mask, it's quite an intervention," he said.
He added that "most governments take advantage of their scientists and listen to them. They don't undermine them and attack them."
Gates did not name US President Donald Trump or any scientist by name.
He said the fact that some countries had performed better than others on testing and mask-wearing was a "purely technical thing, not a political thing."
Trump had a habit of not wearing a mask before his COVID-19 infection â€" and this may have both exposed him to the coronavirus in the first place and raised his risk of developing a more severe infection, experts told Business Insider on October 3.
Gates' comments came after the top US infectious-disease expert, Dr. Anthony Fauci, slammed the Trump campaign on Monday for using his words out of context and without his consent in a recent political ad. This amounted to harassment, he said.
Wearing masks and washing hands are our most important tools, Gates said
Gates, whose charitable organisation, the Bill and Melinda Gates Foundation, has committed more than $US100 million to fight the outbreak, said that social behaviour changes such as wearing masks and washing hands were the most important tools for controlling COVID-19 until "therapeutics or vaccines get out there in big numbers."
The Gates Foundation, which works to tackle complex global health challenges, teamed up with Wellcome and Mastercard in March to commit $US125 million in funding to companies developing treatments for COVID-19.