Travellers from all parts of Sydney will have to quarantine upon entry to Tasmania from midnight Saturday.
The strengthening of the state's border restrictions for Sydneysiders comes in the wake of 23 fresh northern beaches cases recorded in Sydney on Saturday, bring the outbreak total to 40 cases.
Premier Peter Gutwein told reporters in a late Saturday afternoon press conference after being in meetings with health officials all day, he'd been advised to raise greater Sydney to "medium risk" level.
This means travellers from the northern beaches, as well as from any other part of metropolitan Sydney, would be required to spend two weeks in quarantine on arrival.
He said the higher risk rating across Sydney would inevitably impact the Sydney to Hobart Yacht race, due to start on Boxing Day.
"These conditions would make it very challenging for the race to proceed," Mr Gutwein said.
Race organisers have been saying all week they intend running the famous yacht race as planned.
The island state's move towards stricter quarantine requirements comes a day after the northern beaches and several other locations were declared "high risk".
Anybody who has spent time in a high-risk area will not be allowed to travel into Tasmania unless approved by the state's deputy state controller.
Tasmanian contact tracers are chasing up travellers from NSW who have entered the state unhindered since December 11 - the date linked to infection spreader events in multiple Sydney locations.
