Updated 2 p.m. ET

Massachusetts residents eligible for COVID-19 vaccination will be able to pre-register for an appointment at their closest mass vaccination center starting Friday.

Gov. Charlie Baker announced the new registration website, powered by Google cloud computing infrastructure, at a Wednesday news conference.

"The preregistration system is designed to make it easier for residents to secure an available appointment, and we'll soon replace the current process of large numbers of appointments being posted online on Thursday mornings for mass vacination sites," Baker said from a factory in West Bridgewater that was converted to produce personal protective equipment at the start of the pandemic.

Thursday, March 11, will be the final day for the current appointment system, which has had its challenges as hundreds of thousands of eligible residents searched for available appointments. Secretary of Health and Human Services Marylou Sudders said Wednesday that 40,000 new appointments will be made available on the current 'Vax Finder' site Thursday morning, the final day before the pre-registration system goes into effect.

"People should keep in mind that it will probably still take several weeks for eligible residents to be notified that there is an appointment available for them, because we're still receiving a real limited federal supply of vaccine doses," Baker said.

Democrats at the State House have criticised Baker, a Republican, for the state's vaccine rollout and demanded he fix the shaky appointment website while supplies are still limited.

“It's about time. While this should have been done from the beginning, I’m grateful the Governor has finally decided to take my call to establish a pre-registration system seriously," Sen. Diana DiZoglio, D-Methuen, told GBH News. DiZoglio sponsored a bill calling for pre-registration.

DiZoglio is calling for the Legislature to exert more oversight of Baker's handling of the pandemic and vaccination process, with a focus on how contracts are awarded and an audit of the vaccine distribution system.

"We've seen what happened in the past when there was not oversight, and we've seen how things very quickly fell apart when things were left up to the administration," DiZoglio said.

State health officials said Wednesday that federal suppliers will not greatly increase the supply of vaccines coming to Massachusetts until the end of March. The state can expect 150,000 new first doses for the remainder of the month.

Exactly one year after he deemed the pandemic an emergency, Baker said that if supplies were raised to meet demand, the state could administer more than one million shots per month.

"We could probably do 2 million people a month, and that would move the ball in a big way to get us to the point where I start feeling comfortable that we can start thinking about where we are with respect to the emergency order," Baker said.

Baker said there won't be website problems with the new Google-backed pre-registration site similar to what happened when the appointment site crashed last month.

"Google has set up pre-registration sites in a number of other states. They've pressure tested what we have experienced here in Massachusetts with what they've experienced in other states, and they're pretty confident that we won't have any issues," Baker said.

The state will also dedicate specific days over the next month to vaccinating K-12 educators at its mass vaccination sites: March 27, April 3, April 10 and April 11. Teachers, school childcare workers and other school staff will be asked to self-attest to their eligibility for the shots. Sudders said state officials are also encouraging regional vaccination collaboratives that are not directly operated by the state to also dedicate specific days to teachers.

Starting Friday morning, at the launch of the new website, eligible residents can sign up and confirm pre-registration by entering personal, contact and medical information into a Google-powered form. They will then be placed in the queue for an available appointment only at the mass vaccination center closest to their zip code. Once appointments become available for users in the queue, they will be sent a unique link for booking their appointment sometime the following week.

The unique booking link and code will be active for 24 hours, at which point a user that failed to book an appointment would be placed back in the queue. The system will also send a weekly notification assuring users that they are still in the pre-registration queue until an appointment slot becomes available.

The state's 2-1-1 system will have operators that can guide less technically-savvy residents through the system to get them pre-registered, and notification will be provided over the phone.