The Northern Territory will open its borders on Friday, July 17.
Chief Minister Michael Gunner has just announced the Territory will end its mandatory quarantine arrangements to all states and territories from 12:01am on July 17.
"This morning I received medical advice that community transmission down south is now tracking at an acceptable risk level," Mr Gunner said.
"Based on the evidence, our Chief Health Officer recommends a 28-day assessment period before opening our borders - which is two COVID-19 replication cycles.
"That is why we are waiting until next month."
NT Opposition leader Lia Finocchiaro this week said she would have opened the borders on Monday.
Mr Gunner said from July 17, arrivals will not have to self-quarantine for 14 days before enjoying the Territory.
"This gives the rest of Australia four weeks' notice, and it gives the Territory four weeks to get ready," he said.
"It gives businesses time to prepare. It gives us time to market the Territory to visitors.
"It gives us time to lock in the gains we've made - and be absolutely certain we aren't putting our progress at risk.
"Twenty-eight days notice makes sure we that we don't stuff this up."
The decision will come too late for the big dry season school break which ends that same weekend.