CHICAGO (CBS) — Illinois Gov. JB Pritzker on Sunday pushed back against critics of his plans to reopen Illinois.

After a rally on Saturday outside the Thompson Center, Pritzker appeared on CNN Sunday and reiterated that the state will not reopen until certain standards have been met.

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“We’re being very careful,” Pritzker said. “We have a 28-day period that we’re in now during the month of May in which we’re watching all these numbers, monitoring them. We’ve done a lot to make sure we’re keeping these numbers moving in the right direction. We will not reopen unless we meet all the standards that I’ve set for doing so.”

Pritzker unveiled his Restore Illinois plan last week. He said the state would not be able to fully reopen until there is a vaccine, a widely available and effective medical treatment, or enough widespread immunity that there are not any new cases of the disease.

However, he said there would be intermediate steps, and some parts of the state might be able to begin reopening before others.

The plan divides the state into four regions – Northeast Illinois, North-Central Illinois, Central Illinois, and Southern Illinois – each of which is made up of a group of the state’s 11 emergency medical services regions.

The plan is now in Phase 2.

To move on to Phase 3 of the reopening plan, a region must maintain a COVID-19 positive test rate of 20% or lower, and no more than a 10 percentage-point overall increase in cases for more than 14 days; have no overall increase, and maintain overall stability in virus hospitalizations for at least 28 days; and maintain a surge threshold of 14% availability of ICU beds, medical-surgical beds, and ventilators.

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Under Phase 3 of Restore Illinois, non-essential manufacturing and other non-essential businesses would be allowed to reopen under approved safety guidance from the Illinois Department of Public Health. Remote work, whenever possible, would still be encouraged.

Barber shops and salons would be allowed to reopen; and gyms and fitness clubs would be allowed to offer outdoor classes and one-on-one training; all with IDPH guidance. State parks also would be allowed to reopen, as would limited childcare and summer programs. Non-essential public gatherings of up to 10 people would be allowed, as opposed to the current limit of only essential gatherings of up to 10 people.

Pritzker declined to predict which region might be the first to move on to the third phase of reopening. But he said it would not happen anywhere before May 29.

To move on to Phase 4, a region would have to show continued declines in positive COVID-19 test rates and hospitalizations, and maintain hospital surge capacity.

Under Phase 4, restaurants, bars, cinemas, theaters, retail stores, and gyms would be allowed to reopen with new capacity limits, under IDPH-approved safety guidelines. Schools, summer and fall programs, childcare, and higher education institutions also would be able to reopen with IDPH guidance. Outdoor recreation programs and public gatherings of up to 50 people would be allowed.

Phase 5 would be a full reopening, including the return of large conventions, festivals, and other large-scale events; and will only be possible with a vaccine, a widely available and effective treatment, or an elimination of new cases over a sustained period of time.

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The governor said the guidelines of the reopening plan are subject to change, depending on how the outbreak evolves, and the recommendations of experts.