CDC Director Robert Redfield was questioned by House lawmakers Tuesday about the spread of the coronavirus.

When asked if he was aware of evidence that a physical barrier on US borders would help stop the illness, he replied: "Not that I've seen."

But hours earlier, President Donald Trump had tweeted, in response to the coronavirus outbreak: "We need the Wall more than ever!"

It was the first time the president linked his signature anti-migration policy to efforts to halt the spread of the illness.

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Robert Redfield, the director of the Centers for Disease Control and Prevention (CDC), shot down President Donald Trump's claims that a physical wall on US borders would help fight the coronavirus outbreak.

Redfield appeared before the House of Representatives on Tuesday, where he faced questions about his agency's efforts to tackle the coronavirus crisis.

During the testimony Redfield was asked by Rep. Katherine Clark, a Democrat from Massachusetts, whether there are any agency recommendations that "structural barriers at our borders would be of any use in mitigating the outbreak of" coronavirus.

"Not that I've seen," Redfield said.

Watch the exchange here:

—DNC War Room (@DNCWarRoom) March 10, 2020

Redfield's claim came just hours after Trump linked the completion of a border wall between the US and Mexico — a signature promise in his 2016 presidential campaign — to efforts to contain the coronavirus.

"Going up fast. We need the Wall more than ever!" he wrote.

In the tweet Trump had also shared a message from conservative youth activist Charlie Kirk, who wrote: "Now, more than ever, we need the wall. With China Virus spreading across the globe, the US stands a chance if we can control of our borders. President Trump is making it happen I explain why this matters & SO MUCH MORE!"

Refering to the novel coronavirus as "China virus" by Kirk and other prominent US conservatives has been denounced for fueling racist stigmatization, and contradicts advice from the World Health Organization to not pin a geographical label on the illness.

In his testimony Tuesday, Redfield said he agreed that it was wrong to call the illness "the China coronavirus."

"It's absolutely wrong and inappropriate to call this the Chinese coronavirus, I assume you would agree with that," Rep. Lois Frankel, a Florida Democrat, asked Redfield.

"Yes," Redfield replied.

Business Insider is not aware of any cases of the coronavirus suspected to have been transmitted by a person migrating over the US-Mexico border.

Tuesday is not the first time Trump's claims about the coronavirus have clashed with the information provided by US health officials.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, at a White House meeting last week rebutted the president's claim that a novel coronavirus vaccine would be available imminently.