BRUSSELS: The United States has seen Russia stocking up on blood supplies, inching troops closer to Ukraine's borders and flying in more combat aircraft, US Defense Secretary Lloyd Austin said on Thursday, dismissing Moscow claims of withdrawal.

"I was a soldier myself not that long ago. I know firsthand that you don't do these sorts of things for no reason," said Austin, a retired Army general. "And you certainly don't do them if you're getting ready to pack up and go home."

US defense secretary heads to Europe for NATO talks, visit troops