Wales' tourism sector could "struggle to generate any significant revenue" before next Easter at the earliest, according to the economy minister.
Ken Skates said it could be longer, depending on "how soon we can get the virus under control".
Tourism is estimated to be worth £3bn to the Welsh economy and bosses have also expressed fears for its future.
"We have to protect the 2021 season by making sure we get rid of the virus as soon as possible," said Mr Skates.
"The tourism sector is really going to struggle to generate any significant revenue before certainly Easter of next year, possibly the summer of next year," he told BBC Radio Wales' Sunday Supplement.
Mr Skates said an "incredibly generous" package of support had been put in place for businesses but it was "vitally important" that people continued to follow the lockdown restrictions to "kill off the virus" as soon as possible.
He went on to say that some sections of the tourism industry, such as caravan parks, could see some return of business activity, but only if it was safe, and as part of an easing of lockdown measures.
Restrictions currently ban all but essential travel in Wales and visitors are not allowed to come from over the English border despite more relaxed rules there.
The minister also warned that unemployment could increase, depending on how the economy recovers.
Latest figures showed the number of people claiming unemployment-related benefits leapt in April, the first full month of the coronavirus lockdown.
"Unemployment could rise to 10%, possibly more - it depends on the recovery though," said Mr Skates.
"If it is a V-shaped recovery then we'd expect to be able to get people back into work much sooner," he said.
David Jones, the Conservative MP for Clwyd West, told Sunday Supplement that reopening zoos and other attractions with "wide open spaces" should be a "priority" when it was "safe to do so".
He pointed out they were facing crippling costs and unable to furlough staff as they had to continue to look after the animals.
Mr Jones said it was costing about £30,000 each week to maintain the Welsh Mountain Zoo in Colwyn Bay which has been closed since March.
"Rural areas are just the right sort of assets to have for a tourism destination so we are really hoping that people will come back here, but we need businesses to survive," he said.