UEFA president Michel Platini on Friday said that he was open to all options for the European championships in 2020, a day after the ruling body said that the tournament would be held across the continent.
"It's a blank page at the moment," said the former France captain.
"I can't tell you where we're going to go. We haven't yet gone into the details. It's a one-off decision."
Platini first mooted the idea of holding the 60th anniversary of European football's premier competition in a number of countries before the final of this year's edition in Poland and Ukraine, which was won by defending champions Spain.
On Thursday, UEFA's executive committee was virtually unanimous in supporting the idea, which Platini said had been circulating for a number of years and had been the subject of numerous meetings and discussions with national associations.
Many fans suggested that the decision, opposed only by Turkey which had previously submitted a bid to host the tournament in eight years' time, would lead to increased costs and could destroy the atmosphere of the competition.
But Platini, who has argued that a Europe-wide competition would relieve pressures on one or two host nations given the current parlous financial climate in many countries, said more work was required to thrash out the detail.
"There are political decisions and geographic decisions," he told reporters in Nyon, Switzerland, where UEFA is based.
"It's not a case of a fan watching his team in Cardiff (Britain) then in Astana (Kazakhstan) and then in Sweden.
"Nothing is decided at the moment. I put forward the idea, the associations voted. I propose things and the executive committee decides."
UEFA secretary-general Gianni Infantino said that the project would be re-examined in January or March next year and that host cities would be chosen in early 2014.
"We're looking at something bigger and more united," Platini said. "Countries that would never have had the chance to host the Euros will be able to participate in this festival of football.
"The situation is difficult in Europe. It's hard to ask one country to invest in 10 stadiums like in Ukraine. There's also the idea of belonging to a European country. It's a great idea to mark the anniversary.
"The Euros will go to the fans. It'll meet supporters. In previous years, they had to go to the Euros. Everything will be done so that the fans are able to get to games."
England's Football Association (FA), meanwhile, registered their interest early in staging the semi-finals and finals at London's Wembley stadium, while the Scottish FA also said they would be keen to participate.
The host cities bidding process will begin in March, with decisions on venues set to be made in early 2014.
The next European championships in 2016 are to be held in France, with an increase in the number of teams from the current 16 to 24.