The US state of Alaska has activated emergency crisis protocols that allow 20 medical facilities to ration care if needed as the state recorded the nation's worst Covid-19 diagnosis rates in recent days, straining the state's limited health care system.

The declaration covers three facilities that had already announced emergency protocols, including the state's largest hospital, Providence Alaska Medical Centre in Anchorage. The state's declaration also includes the other two hospitals in Anchorage and facilities across the nation's largest but sparsely populated state, according to an AP report.