The Big Apple is making “extraordinary” progress in the battle against the coronavirus but still not enough to reopen the city, Mayor Bill de Blasio said Friday, as he announced a new test and tracing system.

Hizzoner said there was a significant decline in the number of virus-infected patients in the city’s ICUs since the daily peak last month at nearly 900 people.

On Wednesday, 568 people were in ICUs with the contagion, according to the most recent city stats, which have a two-day lag. One fewer person was in intensive care on Tuesday, but the trend is still promising, according to the mayor.

“That number is really a crucial number because it talks about the most extreme impact this disease has had,” de Blasio said. “The ones in the ICUs are facing the greatest threat. That number is going down. It means a lot more lives are being saved.”

The number of people admitted to the city’s hospitals was up from 79 to 102 between Tuesday and Wednesday, but those figures have seen a steep decline since the daily peak in late March of 850 admissions.

“Unfortunately, it’s another day where we see the big picture is unquestionably good but still day to day,” the mayor said. “Still overall, much lower numbers, [but] not yet what we need to take the next step towards loosening restrictions.”

The percentage of people tested citywide who are positive for COVID-19 dipped from 16 percent Tuesday to 14 percent Wednesday.