In a memo sent on Tuesday to employees, the Seattle coffee giant said it was responding to last week's ruling by the US Supreme Court.

In a 6-3 vote, the court rejected US President Joe Biden's plan to require vaccines or regular COVID-19 testing at companies with more than 100 workers.

"We respect the court's ruling and will comply," Starbucks Chief Operating Officer John Culver wrote in the memo.

Starbucks' reversal is among the most high-profile corporate actions in response to the court ruling.

Many other big companies, including Target, have been quiet on their plans.

On January 3, Starbucks said it would require all employees to be vaccinated by February 9 or face a weekly COVID-19 test requirement.

At the time, Culver said it was the responsibility of Starbucks' leadership "to do whatever we can to help keep you safe and create the safest work environment possible".

In Tuesday's memo, Culver said the company continues to strongly encourage vaccinations and booster shots.

The company also told workers on Tuesday that they should not wear cloth masks to work, and should instead use medical-grade surgical masks.

Starbucks had required workers to reveal their vaccination status by January 10.

The company said on Wednesday that 90 per cent have reported and the "vast majority" are fully vaccinated.

Starbucks employs 228,000 people in the US.

Australian Associated Press