President Joe Biden’s plan to rescue Afghans who aided U.S. forces faces multiple logistical challenges, as the Taliban begins its reign.

The Pentagon plans to evacuate at least 22,000 Special Immigrant Visa (SIV) applicants, families members, and other at-risk individuals.

“It is a nice goal to have but, realistically, it is going to be a challenge,” one U.S. official said according to Reuters.

Despite pleas from politicians and refugee groups to begin transporting at-risk Afghans months earlier, Biden chose to wait until July. Only 2,000 Afghans made it to the United States at the time of publication.

Evacuation efforts have experienced growing problems that require prudent and precise planning. Otherwise, time could easily run out due to widespread security concerns across the Middle Eastern country since the Taliban has already captured the capitol of Kabul.

U.S. forces temporarily suspended flights from Hamid Karzai International Airport for several hours, after hundreds of Afghan asylum seekers flooded the terminal building, stairway, and runway.

Many of them were so desperate to leave they clung onto U.S. Air Force military transport planes with their arms and legs, even after take off. At least three stowaways plunged dozens of feet to their death while another was found dead in the landing gear well.

The U.S. Army is confident it can control the airport long enough to evacuate Americans and their supporters. It has deployed up to 6,000 troops to bolster security at the airport, and expects U.S. planes to evacuate between 5,000 and 9,000 people a day. The mission is expected to finish in late August.

Different veteran groups and nonprofit organizations urged the president to keep soldiers at the Kabul Airport until at least the end of the month. This would prevent the Taliban from taking over the only safe escape route for Afghans.

Taliban fighters are marching outside the U.S.-controlled facility, and threatening Afghans not to enter otherwise they will open fire.

“Taliban are all around the Kabul Airport [and an] interpreter with a visa told me he cannot get to the terminal,” Australian Foreign affairs and defense correspondent Ben Packham said on Twitter.

 “Taliban fighters are going door to door, and pulling people out, who are not being seen again,” Association of Wartime Allies executive director Kim Staffieri said according to the newswire agency. 

People on both sides of the aisle believe the Biden administration should have started rescuing Afghans weeks sooner.

“We did not need to be seeing the scenes that we ere seeing at Kabul Airport with our Afghan friends climbing aboard C-17s,” Rep. Jason Crow (D-Colo.) said according to Click Orlando. “It could have been done deliberately and methodically, and we think that that was a missed opportunity.”

Just one base in Virginia is responsible for housing successful SIV applicants, who only began arriving a week earlier.

The president defended his decision to wait, blaming the Afghan government for advising him not to begin the rescue mission too early. He also claimed some Afghans did not want to leave sooner, drawing fierce backlash.

“To me that is extremely, extremely appalling to see that language coming out from the White House,” International Refugee Assistance Project strategy director Betsy Fisher said according to Reuters.

The Lutheran Immigration and Refugee Service confirmed several interpreters, and translators for the U.S. government have already been killed while waiting to be evacuated.

“To suggest that Afghans were not desperately seeking refuge here in the United States is utterly inconsistent with our experience,” president Krish O’Mara Vignarajah said according to the newswire agency.

Mismanaging the Afghan evacuation has delivered a major blow to the Biden administration’s credibility.