UEFA chief Michel Platini said on Wednesday there was "no plan B" to stage Euro 2012 outside Poland and Ukraine and he was confident both nations would be able to co-host the tournament.

European soccer's governing body had criticised Warsaw and Kiev over their sluggish preparations and Platini warned both nations they risked being stripped of the right to stage UEFA's biggest event unless they stepped up their efforts.

There has been speculation, notably in the Polish and Ukrainian media, that UEFA had already started to look at possible alternatives, ranging from switching the whole event to another country such as Spain to asking Germany to co-host with Poland, which has made more progress than its neighbour.

"There is no alternative plan. There is no plan B for Euro 2012," Platini told reporters on a visit to the European Parliament in Brussels.

"We still have some concerns and it will be a challenge. But stadiums are being built and I think we will go to Poland and Ukraine. Today I believe we will be successful in this challenge."

Platini confirmed that UEFA's executive committee would make a final decision in May on whether Poland and Ukraine would be ready on time and if so, which cities will host the matches.