It was statement by American General, who are used to making such boastful claims themselves:
All over news and other media, propagandists are behaving as if Rus made this 2 day claim. Rus didn't make any such bluff.
Gen. Milley says Kyiv could fall within 72 hours if Russia decides to invade Ukraine: sources
Chairman of the Joint Chiefs of Staff Gen. Mark Milley told lawmakers that Kyiv could fall within 72 hours if a full-scale Russian invasion of Ukraine took place, multiple congressional sources tell Fox News.
www.foxnews.com
American Officials made similar bluffs before Iraq war.
There was a claim on US TV that they will occupy Iraq in 30 minutes [though I cannot find online source but I watch that claim on TV in those days].
But below is a documented bluff of American veteran official:
"
Five days or five weeks or five months, but it certainly isn't going to last any longer than that", Defense Secretary Donald Rumsfeld.