A prohibition of gatherings of more than 250 people would apply in Snohomish, King and Pierce counties.

SEATTLE — Gov. Jay Inslee will hold a news conference here Wednesday morning to outline new strategies aimed at containing the spread of the coronavirus in communities throughout Washington.

Inslee reportedly is going to announce a ban on events and social gatherings attended by more than 250 people. Initially the prohibition would be imposed only in Snohomish, King and Pierce counties, the state’s three most populous. The largest concentration of confirmed coronavirus cases are in King and Snohomish counties.

The news conference is set for 10:15 a.m.

The governor will be joined by Snohomish County Executive Dave Somers, King County Executive Dow Constantine and Pierce County Executive Bruce Dammeier. Everett Mayor Cassie Franklin, along with the mayors of Seattle and Tacoma, also will attend.

“We’re really trying to coordinate throughout the region,” Somers said Tuesday. “We are trying to decide as a region on the best course of action to slowing its spread.”

Somers said he is “absolutely worried about the impact” of large events getting canceled, if that’s what the governor orders.

“But it makes all kind of sense based on what we know about the disease and its spread,” he said.

Inslee told reporters early Tuesday that he was still considering using his executive authority to prohibit large gatherings like sporting events.

“I would not be shocked if we have some more news on that in the next few days,” he said. “If we’re going to stop this epidemic, we need to look at what’s coming, not just what’s here today.”