The Prime Minister is warning Australia's international borders will remain closed for the foreseeable future, as his Treasurer notes this week's federal budget assumes Australia will remain locked off to the rest of the world until at least 2022.

Australia's borders were slammed shut in March last year as the coronavirus spread across the world, with the federal government trying to take advantage of the nation's island geography to safeguard it from the worst of the deadly virus.

In an interview with News Corp, Mr Morrison said he did not believe Australians had an "appetite" for opening borders if it meant having to deal with more coronavirus outbreaks, lockdowns and social restrictions.

"We have to be careful not to exchange that way of life for what everyone else has," he said.

In a later post on Facebook, he warned borders would only be opened "when it is safe to do so".

"Australians are living like in few countries around the world today."

Treasurer Josh Frydenberg echoed those sentiments, confirming Treasury's budget forecasts were based on borders opening "next year". 

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume.

Watch

Duration: 1 minute 31 seconds1m 31s

The admission has prompted criticism from the opposition, which argued it is the consequence of ongoing mismanagement of the coronavirus vaccination program and hotel quarantine arrangements.

"Three weeks ago, Scott Morrison said there could be international travel and home quarantine by as early as July," Shadow Health Minister Mark Butler said.

"This morning, three weeks later, he's saying Australia will be locked down forever — which is it?

"Australia needs a clear plan on vaccines and quarantine but all we're getting from this Prime Minister is excuses and failure."

The Prime Minister has previously said he would not put hard dates on vaccination milestones.

Qantas had been planning to restart international flights from October, with chief executive Alan Joyce saying his airline was in discussions with the federal government about when border restrictions would be lifted. 

Health Minister Greg Hunt said Australia would pursue more travel bubbles with countries, beyond the current arrangements with New Zealand, rather than totally open its borders.