On Thursday, President Donald Trump said he was unsure whether he received a coronavirus test on the day of the first presidential debate. It was required that both Trump and Democratic opponent Joe Biden would undergo COVID-19 testing prior to debating on stage.

When responding to NBC’s Savannah Guthrie, Trump said, “I don’t know. I don’t even remember.”

The president repeatedly stated, “possibly I did, possibly I didn’t” to the same question that was brought up multiple times.

The White House has refused to release details on Trump’s last negative COVID-19 test. Experts have said that the president’s negative test is vital in determining who Trump may have exposed to the virus and whether Trump was positive when he debated with Biden.