President Donald Trump wants Americans at the front of the line when Pfizer's COVID-19 vaccine doses are ready.

President Trump's executive order essentially compels companies such as Pfizer to give its American-made vaccines to the United States first.

His team says it would restrict delivering doses to other countries until there is excess supply here.

President Trump warned Tuesday that companies must comply.

"Now, if necessary we will invoke the Defense Production Act, but we don't think it will be necessary," said Trump.

Doing so allows the president to direct private companies to prioritize orders from the federal government.

This comes after Pfizer's Scott Gottlieb confirmed on CNBC that the Trump administration turned down a number of offers to lock in more than 100 million doses of Pfizer's vaccine.

Gottlieb says it's possible Trump's team could stop them from shipping the vaccine to those countries.

He says it's a messy situation. Some of the materials and initial doses the United States will receive will be coming from Pfizer's European facility.

Meanwhile, the FDA confirmed the safety and efficacy of Pfizer's vaccine.

The federal report showed 95% effectiveness and a stronger immunity after the first dose than previously believed.

The FDA called the vaccine, "strongly protective against the virus," while noting the most common side effects are headaches, muscle pain and fever.

In just two days, the FDA will be holding its hearing to possibly give Pfizer emergency use authorization to roll out its vaccine in the United States.

Moderna, based in Massachusetts, will have its on Dec. 17.

President Trump says he expects to have news on Johnson & Johnson's vaccine and a number of others soon.