Trump made the remark about the re-opening of US states amid the COVID-19 pandemic.

Contrary to what individual governors may mandate for their states, Trump said,

Well I have the ultimate authority. President of the United States has the authority to do what the President has the authority to do, which is very powerful. The President of the United States calls the shots…

When pressed about how constitutionally, it is not in the purview of the federal government to dictate such matters to states, and whether he had addressed such matters with governors, Trump said,

I haven’t asked them about it. You know why? because I don’t have to.

When asked to elaborate, Trump replied,

When somebody is the President of the United States, the authority is total. And that’s the way that it’s got to be. It’s total. It’s total…but the authority of the president of the United States having to do with the subject we’re talking about is total…You can look at constitutionally, you can look at federalism…we have the power. Does the federal government have the power? The federal government has absolute power. It has the power.

On the day of the press conference, the United States had over 580,000 cases and 23,000 deaths from COVID-19.

Trump also previously claimed that Article II of the Constitution allows him to “do whatever I want.”

The Washington Post – Trump says his ‘authority is total.’ Constitutional experts have ‘no idea’ where he got that.
Time – Governors Refute Trump’s Claim He Has ‘Total’ Authority on Easing COVID-19 Restrictions
BBC News – Coronavirus: Trump claims ‘total’ authority to lift lockdown
COVID-19 Dashboard by the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University (JHU)