Democrats and Republicans alike voiced concern Tuesday the United States won’t be able to evacuate every American citizen from Afghanistan by Aug. 31, the date American troops are set to leave.

“I don’t think it’s militarily possible, logistically possible,” said Rep. Bill Huizenga, R-Mich, following an intelligence briefing. “Not to mention those SIVs, those special immigration visas folks… the interpreters, they were the support staff.”

Democratic Congresswoman Elissa Slotkin of Michigan, a former CIA analyst, said her office has been working overtime to help nearly 500 Afghans escape so far. She said the U.S. needs to do more to get everyone out. “The stories are harrowing,” she said. “Show that we’re willing to take risks ourselves for those who risked themselves for us.”

The Pentagon insisted it is rapidly accelerating evacuations. In a 24-hour period, officials said more than 21,000 people were transported out of Afghanistan by an international coalition.

The Taliban has also put their foot down amid evacuations. They say U.S. troops must be out by Aug. 31 or there will be consequences.

At the moment, they are blocking Afghans from leaving the country.