Varadkar told Today FM radio organisers are pessimistic about meeting UEFA's requirement they "commit to having at least 25 percent of the stadium full" in matches slated this summer. "We're just very cautious about that," he said. "We just think June is too soon. I think if they continue to insist on that it'll be hard for it to go ahead quite frankly."
Dublin's Aviva Stadium is currently scheduled to host three group matches and a last-16 game in the delayed tournament running from June 11 to July 11. But the games are in doubt as Ireland is still in the grip of tight coronavirus restrictions and the nation has been tethered to the EU's sluggish vaccine rollout. 4,847 have died from Covid-19 in the Republic according to latest official figures.
Pubs, restaurants, bars and non-essential retail have all been shut since Christmas and there are still limits on domestic and international travel.
Earlier this month the Football Association of Ireland (FAI) told UEFA that "owing to the Covid-19 pandemic it is not in a position at this point to provide assurances on minimum spectator levels".
Nine of the proposed 12 host cities for Euro 2020 have committed to allowing crowds of 25 percent of capacity in for the tournament. Bilbao and Munich are the other two cities in danger of being dropped by UEFA.
European football's governing body is due to take a final decision on Friday over where all matches will be held.
Standout matches today