ASHTON KUTCHER - I GOT NOTHING TO SAY ABOUT DEMI MOORE

Ashton Kutcher had no answer when asked if Demi Moore was okay following her nitrous oxide-induced medical emergency -- hopping wordlessly into a car beside a blonde mystery woman Tuesday night.

The video was shot as the actor was leaving a nightclub in Sao Paulo, Brazil -- an agency photog asks, "Is Demi okay?" ... and Ashton keeps mum, piling into an idling vehicle with two acquaintances, one female.

Ashton has yet to speak out on Demi's condition. The two split in November.