Shops, banks and petrol stations will be now be allowed to open over the next two weeks.
A night time curfew remains in place and the general population is still required to self-isolate, with movement restricted to food shopping, farming and getting medical treatment.
The Ha'apai group of islands will remain in hard lockdown after a Covid outbreak was detected there earlier this week.
The latest update from Tonga's Ministry of Health showed a slight decline in Covid numbers.
As of Friday, the Ministry of Health said there were 1,979 active cases.