The move comes in a bid to get more people vaccinated against the virus.
In an address to MSPs Sturgeon said: "Given the current situation – and the need to get more people fully vaccinated before we ease up further – it is reasonable, I think, to indicate now that it is unlikely that any part of the country will move down a level from 28 June.
"Instead, it is more likely that we will opt to maintain restrictions for a further three weeks from 28 June and use that time to vaccinate – with both doses – as many more people as possible.
"Doing that will give us the best chance, later in July, of getting back on track and restoring the much greater normality that we all crave."