The sides finished second in Group I and Group H respectively, with the first leg of the qualifying tie taking place in Kiev on Friday.
While Ribery admits there is plenty of pressure surrounding the play-off, the Bayern Munich man wants France to go into the game with confidence.
"These games are special. It's surrounded by a difficult context. Now, we need to play with no pressure. We should not be scared," he said.
Ukraine have not conceded in their last seven matches and have not lost since October 2012.
Ribery insists Ukraine must be respected, as he added: "It's going to be two difficult games. We should not take things easy against this team or say to ourselves we are already in Brazil.
"They are very strong defensively. They didn't concede many goals. They play well in counter-attack. We need to be ready and get a good result there. Then, we will have to manage the game at home well."
Ribery, who has nine goals for Bayern this season in all competitions, has paid tribute to his club manager Pep Guardiola for his fine form.
The 30-year-old is nominated for the FIFA Ballon d'Or and hailed the impact Guardiola has made since arriving at the Allianz Arena.
"I have more experience. I am more serene and I have less pressure. I know how to handle different situations," he added.
"My confidence comes from the appointment of Guardiola, that helped me a lot. He is a coach who says to me every day that I have to try my luck more, and shoot more on goal.
"I tended to pass the ball at training two metres away from the goals and he said: 'You should have scored, you should have shot.' That's confidence.
"Since he joined the club, I have scored goals for Bayern and the French national team. Hopefully, it will continue."
