Updated at 11:40 a.m. ET

Top officials responsible for making it easier for Americans to get tested for the coronavirus are expected to give an update on their progress at the White House on Saturday.

An initial lack of testing for the virus during the early stages of the pandemic slowed the U.S. response. President Trump has been under pressure to ensure that people who are showing symptoms of the respiratory illness caused by the virus can find out whether they have it.

The White House scheduled a briefing by its coronavirus task force for 12:30 p.m. ET on Saturday.

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Vice President Pence, who leads the task force, said commercial labs have helped boost distribution of tests to states. He said the Federal Emergency Management Agency and Adm. Brett Giroir, a top public health official leading the efforts to expand testing, will provide details on progress.

“We’ve obviously focused on states that have been dealing with the most serious outbreaks of coronavirus: Washington state, California, New York and others,” Pence said.

This week, governors across the country warned that they were seeing shortages of supplies needed for testing, including testing reagents, used to create a chemical reaction to detect the virus, and swabs. On Friday, Health and Human Services Secretary Alex Azar said there had been “tremendous progress” in lab testing and dismissed complaints about shortages as “anecdotal.”

“Usually it’s that the lab people don’t understand that there are alternative supplies in the marketplace that they are perfectly free to use,” Azar said. “Sometimes there’s a lab that doesn’t understand … how much supply there is out there.”

But groups that represents public health labs, epidemiologists and state health officials said late Friday that there were “widespread shortages of laboratory supplies and reagents.”

The Association of Public Health Laboratories said testing should be reserved for health care workers and first responders, older Americans with symptoms and other people at high risk of getting seriously ill from the virus.

The groups said mass testing would quickly deplete supplies, and it instead urged people with mild respiratory illness to stay at home and isolate themselves.

Hospitals have also said health care workers lack masks and other gear needed to protect themselves when treating patients with the virus. Pence said on Friday that there would be an announcement this weekend about what he called “a major acquisition” of masks.

A week ago, Trump and Pence had said there would be a website where people could find out whether they needed to be tested for the virus and direct them to nearby drive-though sites. While a division of Google’s parent company has developed a pilot project in San Francisco, no website for national use has materialized.

After the president thanked Google for developing the website last week, the tech company put out a statement saying the life sciences division, Verily, was only in the “early stages” of such a rollout.

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