The State Department “stonewalled” Sen. Ben Sasse, R-Neb., for “weeks” following repeated requests for information on the number of green card holders stranded in Afghanistan, a spokesperson for the senator told Fox News Tuesday.

In the wake of the collapse of Afghanistan, officials were unable to definitely confirm the number of Americans or Legal Permanent Residents (LPRS), also known as green card holders, who were stuck inside the Taliban stronghold.

The U.S. has evacuated at least 124,000 Americans and at-risk Afghans since the Taliban takeover, but Secretary of State Antony Blinken said Monday that “several thousand” green card holders remain. “This is a national humiliation,” Sasse said in a statement. “Let’s be very clear about this: These men and women are legal permanent residents of the United States.”

“When America gives someone a green card, it’s a promise that their permanent home is here in the United States with us,” the Nebraska senator added.  The Biden administration has touted the evacuation as a success and Blinked called the mass evacuation effort “one of the biggest airlifts in history.”

But officials have also said the U.S. strategy in getting people out of Afghanistan under Operation Allies Refuge by the Aug. 31 deadline was flawed, and President Biden himself called the process “messy.”

The State Department have blamed the Trump administration for the backlog of Special Immigrant Visa (SIV) holders and have claimed there was no indication that the Afghan government would collapse as quickly as it did.

Blinken told lawmakers in a House Foreign Affairs Committee hearing Monday that the department is in “constant contact with American citizens still in Afghanistan who have told us that they wish to leave.”