The U.S. President Joe Biden on Thursday is expected to impose more stringent vaccine rules on federal workers by signing an executive order requiring all government employees be vaccinated against COVID-19, with no option of being regularly tested to opt out, according to a source familiar with the plans.

During a major speech meant to lay out a new approach to combating the coronavirus, the President will also sign an executive order directing the same standard be extended to employees of contractors who do business with the federal government.

The Department of Defense, the Department of Veterans Affairs, Indian Health Service and National Institutes of Health will also complete their previously announced vaccination requirements, which the White House estimates covers 2.5 million workers.

The new announcements move beyond what Biden announced earlier this summer, when he required federal workers be vaccinated but allowed for those who opted out to be subject to stringent mitigation measures. The White House has said the federal government should act as a model for other businesses in their own vaccine mandates, and has praised large companies that require employees to be vaccinated.

Biden plans to announce a major expansion to free testing, a step public health official have said is critical to containing the virus, particularly as children return to school and some workers return to offices.

And he will address the confusion over booster shots, though will not make any new announcements on when additional doses will be authorized for Americans.

The six-pronged plan Biden is set to unveil was finalized by the President and members of his public health team on Wednesday afternoon. He received a briefing in the Oval Office from his COVID-19 response team on the anticipated new steps.

(With input from agencies)