Los Angeles and southern California will be allowed to partially reopen indoor dining and movie theaters from this weekend, Governor Gavin Newsom said Wednesday, as the region hit key health criteria.

Slammed by COVID-19 pandemic winter spike, California has seen a rapid decline in infection rates in recent weeks as a vaccination rollout has delivered at least one dose to nearly a fifth of residents.

A goal of delivering 2 million doses to the state's most vulnerable communities is set to be achieved Friday, triggering a loosening of the "tier" system that determines how counties can reopen at different rates.

"Southern California, you will be a beneficiary of this," Newsom said, while on a tour of a local mobile vaccination site.

"Specifically, LA will be a big beneficiary of this new metric that likely will be met on Friday. And moving through the weekend and into next week, you will see more activity, more loosening of the tiers."

The change would allow indoor dining and movie theaters to operate at reduced capacities, and also confirms that theme parks will be allowed to reopen at limited capacity from April 1.

But Los Angeles County and neighboring Orange County - where Disneyland is located - can still choose to enforce stricter restrictions than the state mandates.

Disney CEO Bob Chapek said this week that the world's second biggest theme park will not be able to reopen until late April, in order to recall staff and train them in pandemic-safety measures.