As the federal government has struggled to mount a cohesive response to the coronavirus threat over the past few weeks, Trump has repeatedly promoted the administration’s move in late January to bar entry from foreign nationals who had recently been in China and institute a mandatory two-week quarantine for U.S. citizens returning from the epicenter of the outbreak.

On Tuesday morning, Trump claimed his campaign trail pledge to build a wall along the U.S.-Mexico border would also aid in containing the coronavirus, tweeting the structure is “Going up fast” and “We need the Wall more than ever!”

Mark Morgan, the acting commissioner of U.S. Customs and Border Protection, told Fox News on Saturday, “We’re taking our lead from the CDC and [Health and Human Services] and other health care providers.“ He added CBP is represented on the White House coronavirus task force.

“We’re very confident that as the health risks shift or change and we’re asked to operationalize that, no matter what that is, CBP is ready to do that to include the southwest border,“ Morgan said. Thus far, only seven cases of coronavirus have been identified in Mexico.

Redfield’s break with Trump comes after the CDC director drew attention on Friday for heaping praise on the president during his visit to the agency’s headquarters in Atlanta.

“First, I want to thank you for your decisive leadership in helping us put public health first,” Redfield told Trump, as reporters looked on. “I also want to thank you for coming here today and sort of encouraging and bringing energy to the men and women that you see that work every day to try to keep America safe. So I think that’s the most important thing I want to say.”

Among the various scrutinized aspects of the administration’s handling of the outbreak, the CDC has received widespread criticism for its failure to promptly produce a coronavirus test for Americans as well as for its decision to not use a test developed by the World Health Organization in the interim as the epidemic worsened.

Health and Human Services Secretary Alex Azar acknowledged on CNN on Tuesday the administration did not yet know the total number of Americans who have been tested because “hundreds of thousands of our tests have gone out to private labs and hospitals that currently do not report in” to the CDC.

The secretary said the administration is working with the agency and the private partners to get a reporting system “up and running hopefully this week” to track that data.

Redfield told lawmakers that nearly 5,000 people have been tested through public health labs as of Monday and said he anticipated that commercial testing companies would have stepped forward earlier to work with the federal government to develop more tests.

“I would have loved the private sector to be fully engaged eight weeks ago,” he said.

Brianna Ehley contributed to this report.