Boston Mayor Marty Walsh said when the city's offices are able to start reopening on June 1, it will likely be at a lower capacity than the 25 percent that the state allows.

"I don't think we'll have 25 percent capacity at any office in the city," Walsh told Boston Public Radio on Friday. "I'm asking people to work from home still, and I'm asking as you ramp up your offices, you ramp it up with a smaller skeleton crew, if you will, and you build up to capacity."

State guidelines from Gov. Charlie Baker state that businesses across Massachusetts may have employees in office spaces again starting Monday, with only 25 percent capacity filled to allow for social distancing, while Boston offices can start reopening on June 1.

Walsh said he is asking businesses to consider staggering start and end times to limit traffic, and continue to have employees work from home when possible. He advocated for a cautious and measured reopening, and said he'd rather go slow to avoid a potential second wave of COVID-19.

"I've seen stories of what happened in Florida, Alabama, Texas, just jumping the gun and opening up really fast, all of a sudden now they're having mini breakouts all over the place of coronavirus. We can't afford to have that in Boston," said Walsh. "When we reopen society, unless it's an absolute necessity, we can't be shutting things down again. I have no control over that, but in some ways we do have control over it, if when we do go back to work we all wear masks, make sure we're social distancing."

Transportation is a concern for the mayor, he said, as businesses begin to reopen for on-premises work; he said the MBTA should re-evaluate their plan for ramping up service.

"If you see large crowds on the MBTA and people on top of each other, then I'm going to advocate for limiting the people on the trains and increasing service," Walsh said. "If we're doing all this work in the workplace to make sure they're social distancing, physical distancing ... then at the end of the day, they all go home and they're on the bus at the same time, that defeats the purpose. That doesn't help what we're doing."

While businesses have been grenlit to reopen at a significantly reduced capacity, Walsh said restaurants will open much more slowly.

"We've had conversations, first internally then reached out to cities like Seattle, and watched what's going on in England, where they created a program where restaurants that don't have outdoor dining, can have outdoor dining," Walsh said.

He said the city's licensing board created a waiver application for restaurants to request outdoor dining in an effort to serve guests while maintaining social distancing guidelines. According to medical experts, the virus is much harder to contract with proper ventilation, including just by being outdoors.

Walsh said the knowledge around COVID-19 changes so often, policymakers need to be cautious, flexible and willing to adapt, because without a vaccine, society is stuck with the virus for an extended period of time.

"We're not through it, we're not even halfway through it," said Walsh, noting social distancing restrictions will likely extend into 2021.

"People continue to die every day because of this virus. I understand the anxiety, but people have done such an incredible job for the last two and a half months, three months. Let's not just open the window and throw it out the window."

Walsh said he took both a diagnostic test and an antibodies test for COVID-19 last week; he came up negative for currently having the virus, and his antibodies test has not come back yet.

During this segment, Walsh also took calls from listeners.