Apple will shut more U.S. stores this week - one of the busiest shopping times of the year.

COVID-19 cases continue to increase - forcing companies to again close retail locations to mitigate its spread.

Apple said Sunday it would close all of its stores in California and Tennessee. This will add to dozens of stores in Los Angeles closed last week after California reported the most COVID-19 daily cases since the pandemic began.

Total cases in the U.S. have reached more than 18.2 million. More than 324,000 people have died.

The company's stores in the UK - located within areas under tier 4 restrictions - will also be closed this week. This includes 15 of the company's outlets in London and a store in Wales. The UK has enforced emergency lockdowns following the discovery of a new strain of coronavirus.

Apple said two stores in Mexico and Brazil will be closed from Monday. Other outlets in the region will remain open but will be transitioned to "Express" stores that will have limited operations.

Last week, Apple re-closed 18 stores in Germany and the Netherlands as the countries re-imposed coronavirus restrictions due to rising new cases.

As of this week, Apple has closed down 95 stores globally - about a fifth of its retail footprint. Most of the stores that have remained opened have been converted into "Express" shops for storefront pickup of online orders. Genius Support is also still available in some stores.

Apple said that some stores will still cater to walk-in shopping and customers without an appointment. However, the availability will be heavily dependent on local restrictions.

The closing again of Apple's stores this week is expected to negatively affect sales in the short term. This week is one of the busiest shopping weeks of the year as people scramble to purchase last-minute gifts.