The Australian apologised to Kvyat, a former Red Bull teammate, and accepted full responsibility.
«I obviously don’t feel good about what just happened,» he said.
«As soon as I went down the escape road I guess it was just a sense of urgency and a bit of panic, if you will. Just trying to minimise damage and lose as little time as possible.
«I found reverse and started going and to be honest I had no idea he was there. I guess the urgency stopped me from looking,» he added. «I just thought he would have cut back and stayed on track.
«Kind of crappy on my part and I certainly feel bad for the team and for Dani … I feel pretty small at the moment.»
Ricciardo has had a difficult time since he left Red Bull at the end of last season as a race winner and joined the French manufacturer.
A winner in Baku in 2017, the Perth driver has scored points in only one of four races this season as has teammate Nico Hulkenberg.
«It was looking quite good for us, we had started to pick up the pace and closing on Dani, I saw a gap so I thought I’d have a go,» he said.
He later told the Renault website: «It was a bit of urgency on my behalf and I didn’t think straight for a few seconds, so I have to take that one on the chin.
«The team certainly deserved more today. We were bringing on a nice rhythm there and had some good pace on the Medium to continue on and we probably could have scored points.»
Kvyat accepted Ricciardo’s apology in good spirit.
«These things happen, it’s racing like I always said when I make a mistake,» said the Russian, who has been in a few high-profile collisions in his time.
«I was a bit disappointed right in the moment but now what can you do about it? There was potential for maybe a point or two today.»
Valtteri Bottas won the race on Sunday to retake the Championship lead from teammate Lewis Hamilton after a fourth successive one-two finish for Mercedes.