Tasmania has closed its border to Perth and the WA region of Peel after new coronavirus cases sent the two areas into lockdown.
The regions were declared high risk as of 10am on Tuesday, meaning no one can enter Tasmania unless they have special permission from the deputy state controller
"I would stress to Tasmanians, if you don't need to travel interstate, don't travel," Premier Peter Gutwein told reporters.
"Right now we have a number of states scrambling to get on top of the Delta strain of the virus."
Perth and Peel were sent into a four-day lockdown on Monday night after a second local case was recorded, a man aged in his 30s who tested positive to the Delta variant.
Tasmania has already banned travel from 33 local government areas in NSW, including the city of Sydney.
Travellers from Darwin and two other NT LGAs are also banned, while Tasmania considers a host of premises in Queensland, Victoria and New Zealand high risk.
Mr Gutwein said three workers, who returned from the Northern Territory's Granites mine where a person tested positive last week, have returned negative results in their first round of testing.
Two are quarantining at home, the other is in hotel quarantine.
Mr Gutwein said the state government is considering making face masks mandatory at major events.
Under current rules, masks are only mandatory at Tasmania's airports and at the Spirit of Tasmania ferry terminal in Devonport.
Mr Gutwein said the state has adequate supplies of AstraZeneca vaccines for people under 40 after it was announced on Monday night that the demographic was now eligible to receive the jab.
Almost 37 per cent of Tasmania's eligible population have received their first COVID-19 vaccine and more than 11 per cent are fully vaccinated.
Mr Gutwein said the state government was "in discussions" with the AFL about the prospect of Tasmania hosting additional matches.