Portugal international forward Cristiano Ronaldo has insisted that his side need to win against Azerbaijan on Tuesday to stand any chance of qualifying for the World Cup finals in Brazil.

The European nation will head into the game in Baku third in Group F with eight points from five matches, four points behind leaders Russia.

"We have zero room for error from here on," he told the Portuguese FA's official website.

Ronaldo is suspended for Tuesday's fixture but will still travel with his teammates to Azerbaijan.

"The easiest thing for me would have been to return to my club, but I said that I wanted to stay," said the Real Madrid forward. "I feel that my presence with the team is important.

"I can still contribute something to the team even when I'm not playing. I'm a bit sad that I can't help the guys out there on the pitch, but I will encourage the team to give their all and get a good result."

Israel are currently second in the group, level on points with Portugal.