Dana White's catching some flak online after warmly greeting Andrew and Tristan Tate at a Power Slap event ... welcoming them back to the United States.
The president of the UFC was out Power Slap 12 in Las Vegas Friday night ... and, video of him dapping up the controversial brothers is circulating online.
Watch the clip for yourself ... Dana pulls the brothers in for a quick hug before yelling out "Welcome to the States, boys.