UEFA has announced that the next meeting of its Executive Committee, due to take place on May 27, has been postponed until June 17 to allow for more clarity over whether certain cities scheduled to host European Championship games this year will be able to do so in 2021.
The tournament, proposed to be held across 12 cities in 12 different countries, was postponed by a year due to the coronavirus pandemic.
UEFA said that "the existence of some remaining open points regarding a small number of proposed venues for the rearranged UEFA EURO 2020 next year" was the reason for moving the next meeting of its Executive Committee.
The announcement comes soon after UEFA President Aleksander Čeferin suggested the number of cities hosting tournament matches may be reduced.
"We've had conversations with nine cities and everything is set," Čeferin said, speaking to beIN Sports.
"With three cities, we have some issues.
"So we will discuss further.
"In principle, we will do it in 12 cities but if not, we are ready to do it in 10, nine or eight."
UEFA has not specified which venues are ready for games in 2021 and which are not, although organisers in Scottish City Glasgow, which is schedule to host three group-stage matches and one in the round of 16, have insisted they will be able to do so.
Wembley Stadium in the English capital London is due to host the semi-finals and final, among other matches.
Venues in Munich in Germany, Italian capital Rome, Russia's St Petersburg and Azerbaijani capital Baku are planned to stage one quarter-final each, but group matches.
Copenhagen in Denmark, Bucharest in Romania, Dutch city Amsterdam, Irish capital Dublin, Bilbao in Spain and Budapest in Hungary are the other proposed venues.
At the last meeting of its Executive Committee, UEFA approved the release of €236.5 million (£206.2 million/$256.1 million) to support its member associations as they deal with the financial consequences of the pandemic.