Many jobs have come with increased stress levels during the coronavirus pandemic, from ICU staff to Walmart greeters. Now officials who’ve been keeping tabs on FDA commissioner Dr. Stephen Hahn are wondering whether he can weather the strain of defending science while working for the Trump administration, according to a New York Times report.

Hahn has been squeezed between expressing his professional opinions and toeing the administration line on topics such as hydroxychloroquine and COVID-19 vaccines. (Hydroxychloroquine may cause a heart rhythm disorder or drug-induced sudden cardiac death, according to the Centers for Disease Control and Prevention (CDC).) He has gamely fielded questions raised about statements made by President Trump — including on whether the coronavirus is deadly and the possibility of a vaccine being will be ready by Election Day, November 3, 2020.

According to the Times, the oncologist and former hospital administrator was blocked from calling diagnostics companies about producing tests to detect exposure to COVID-19 early in the pandemic, even though former FDA commissioner Scott Gottlieb recommended it and routinely made such calls under Trump, the Times reported. Department of Health and Human Services Secretary Alex Azar denied exerting such political pressure. After the Centers for Disease Control and Prevention’s initial COVID-19 diagnostic was found to be inaccurate, the FDA under Hahn rushed to grant emergency use authorizations (EUAs) for many private companies’ self-validated tests, only to have to withdraw some of those authorizations later.

The FDA also initially resisted granting EUAs for masks made in China for healthcare workers’ use, then reversed course under pressure to ease the shortage of personal protective equipment. The agency began issuing EUAs for the Chinese respirators, only to revoke many of them several weeks later for faulty construction that may have jeopardized the health of front line workers. Similar issues have plagued the agency over antibody tests.

Many Hahn colleagues and longtime FDA observers told the Times that Hahn is doing his best to lead the agency under very difficult circumstances. U.S. Rep. Diana DeGette (D-Colo.) heads the oversight panel of the House Committee on Energy and Commerce, which keeps tabs on the FDA.

“I think some mistakes have been made. I think probably Dr. Hahn has learned from those mistakes,” DeGette told the newspaper. “My perception is he’s trying to accommodate real efforts to treat the virus.”

Trump is keeping up the pressure on the softspoken Hahn, the Times reported. In a recent news conference, the president complimented the FDA commissioner for “really speeding up the process of therapeutics and vaccines.”

“It’s very important, Stephen,” Trump said. “Can you move it faster, please, OK? Thank you, great job.”