Travelers entering the US from Europe waited for hours in long lines Saturday as new coronavirus screenings led to bottlenecks at major airports, the Washington Post reports. The Trump administration unveiled its new “enhanced entry screenings” on Friday, which route passengers on flights from 26 European countries through 13 US airports, including Chicago’s O’Hare and Dallas-Fort Worth.

The new screenings, which include an examination for symptoms and medical histories and instructions for self-quarantine — but not coronavirus tests — were meant to help slow the spread of the virus that has spread quickly across Europe.

But photos on social media showed hundreds of people waiting in close proximity to each other, which is contrary to the CDC recommendations for people to practice social distancing.

The Twitter account for O’Hare International Airport in Chicago posted photos of local staff giving out water and snacks to people stuck in the long lines.

President Trump acknowledged the airport delays in a tweet on Sunday, saying the US is “moving as quickly as possible, but it is very important that we be vigilant and careful.”

Chad Wolf, acting secretary of Homeland Security, tweeted that the agency was aware of the long lines and was working on adding additional screening capacity. “I understand this is very stressful,” Wolf tweeted. “In these unprecedented times, we ask for your patience. It currently takes ~60 seconds for medical professionals to screen each passenger. We will be increasing capacity but the health and safety of the American public is first & foremost.”

Illinois Gov. JB Pritzker tweeted “the federal government needs to get its s@#t together. NOW,” and criticized the Trump administration for the situation. “The crowds & lines O’Hare are unacceptable & need to be addressed immediately,” he said.

As of Sunday morning, there were more than 2,700 known cases of coronavirus infection in the US, with West Virginia the only remaining state with no cases reported.

Update March 15th, 12:55 PM ET: Added comment from President Trump