With the omicron variant surging in Massachusetts and putting stress on the state's health care system, Gov. Charlie Baker is sending up to 500 members of the National Guard to support health providers and is reinstating the recommendation — but not ordering — that everyone wear face coverings in indoor public spaces.

"There's no question the next few weeks will be enormously difficult for our health care community. There are staff shortages, sicker patients and fewer stepdown beds available, again, because of those staff shortages. The steps we're announcing today are designed to support them so that they can continue to care for patients," Baker said a State House press conference Tuesday morning.

The guard members will assist with nonclinical needs at 55 of the state's hospitals and 12 ambulance services starting Monday. The guard will provide transportation within and between medical facilities, observe patients, provide security and deliver food. Three hundred guard members will begin training with hospital officials and guard trainers this week.

The Department of Public Health also ordered hospitals to postpone or cancel all nonessential procedures and surgeries that could result in admission to the hospital, starting Monday.

Baker and DPH are also increasing mask recommendations. They advise everyone, regardless of vaccination or booster status, to wear a face covering in indoor public spaces to cut down on the spread of the virus. Asked why the recommendation came as a DPH advisory and not a statewide mandate, Baker said vaccines and testing have put the state in a very different place than where it was several months ago.

"I have no interest in putting a mandate on this issue, given all the tools that are available on a statewide basis on the people of Massachusetts. If locals wish to pursue alternative options, they can do so. We issued a mask mandate last fall because we had no other options available to us," Baker said.

Baker said the new recommendations will not affect schools, and the latest uptick in viral spread will likely not lead to school shutdowns or remote learning.

Asked about Boston Mayor Michelle Wu's order yesterday to require proof of vaccination at indoor public spaces like restaurants, theaters and gyms, Baker said his administration would assist municipalities that chose to go beyond the state's guidelines. The governor would not say whether he approves of Wu's order. Baker's office added that the governor does not oppose cities and towns implementing vaccine requirements.