NSW Premier Gladys Berejiklian has appealed to the state's youth to modify their social life as the state enters a critical phase of the coronavirus pandemic.
"We are on a knife-edge, and we are about halfway through what is a really critical period," she told Sydney radio Triple M on Thursday.
She was speaking a day after announcing travellers returning from Victoria to NSW would be forced into hotel quarantine for 14 days at their own expense.
"When we realised how bad Victoria's situation was we know we had four-to-six weeks of a real nail-biting situation and we are about halfway through," she said
She thanked the 22,000 people who presented for testing for COVID-19 on Wednesday but urged young people to curb their social life, particularly in the next few weeks.
"To the young people, try and modify the number of places that you go to. If you have the virus and you go out five times a week to different places you could potentially be spreading it to five different locations, and then we have to contract trace everybody."
She warned people had to social distance, even with friends, as Victoria had shown that the greatest spread of the disease happened among friends and family members.
"It only takes a few cases to get out of control."
She also confirmed that Queensland Premier Annastacia Palaszczuk didn't notify her she was shutting the border to NSW.
"She didn't actually," Ms Berejiklian said.
"I said to the boys we've got to win State of Origin this year. Everybody does everything in a different way and we move on!"
Australian Associated Press
