Antony Blinken actually said...
The only way to, actually, implement something like a no fly zone is to send NATO planes into Ukrainian airspace, and to shoot down Russian planes. That could lead to a full- fledged war. And Europe, President Biden has been clear, that we are not going to get into a war with Russia.
Context
Blinken explains the risks associated with imposing a no-fly zone over Ukraine, reiterating the U.S. stance on avoiding direct military conflict with Russia.
03/04/2022