Western Australia Premier Mark McGowan has announced the state will push back its planned reopening date of February 5.
A revised date has not been set, with McGowan saying it will be considered over the next month. He said the Omicron variant meant it was not safe or responsible to re-open now.
"It would be reckless and irresponsible to open up now. I can't do it," he said.
McGowan said he would like to see WA reach 80 or 90 per cent triple dose coverage. Currently 25.8 per cent of West Australians aged 16 and over have received a third dose.
McGowan said he wanted to avoid widespread Covid deaths like what has happened in the eastern states. WA has only recorded one death so far from the virus.
"NSW is sadly recording 25 Covid deaths a day," he said. "Let's just take a deep breath, acknowledge that it's very difficult over there, and we've got to do our best to avoid that occurring here."
McGowan said the state's hard border would stay in place on February 5, but travel exemption rules would be relaxed from that date.
All entrants will have to self-isolate for 14 days, be triple dose vaccinated, and undertake an onerous testing regime.
International entrants will have to undergo seven days of hotel quarantine and seven days of home quarantine.
"As the Prime Minister [Scott Morrison] has said, Omicron has changed everything and right now we don't know the full picture of what Omicron could mean," McGowan said.
"There is insufficient data to make meaningful assumptions of what it would look like once Omicron takes full effect and case numbers peak over east, except that we know, because of case numbers, it is a very bad situation."
WA's Chief Health Officer Dr Andy Robertson said opening up on February 5 would lead to 500-1000 community cases within a couple of days.
The decision was met with anger on social media by people who have not seen their families for a long time.
About 6000 interstate and international passengers are due to touch down at Perth Airport on February 5.
"I know this decision will be unpopular with many people as holiday plans and some family gatherings will have been disrupted," he said. "For that, I'm sorry. I understand exactly what this means for many people who were hoping to reunite without any restrictions."
McGowan announced the February 5 plan six weeks ago to coincide with the state reaching the 90 per cent double-dose vaccination milestone.
However, WA's Covid outbreak continues to grow, now reporting five new local Covid cases.
Four of the cases are close contacts, two of whom were in quarantine, with the others potentially infectious in the community. The source of the final infection is unknown.
There are now 79 active cases in WA, with 23 in hotel quarantine, 56 in self-quarantine and none in hospital.
McGowan's suspected February 5 backflip comes after growing pressure from doctors and nurses over the Omicron threat.
WA has remained closed to the rest of the country for the majority of the pandemic.