The United States has less than a week to evacuate approximately 1,500 Americans still in Afghanistan. Secretary of State Antony Blinken said Wednesday night that U.S. officials are in contact with 500 of them and have provided instructions on how to safely access the Kabul airport before American forces withdraw from the country on August 31st.

“For the remaining roughly 1,000 contacts that we had who may be Americans seeking to leave Afghanistan, we’re aggressively reaching out to them multiple times a day through multiple channels of communication,” Blinken added.

Some of the 1,000 names unaccounted for on the State Department’s list may have already left the country or have decided to stay in Afghanistan permanently, Blinken explained. Others may not be American citizens, but wound up on the list in error.

According to the White House, the U.S. has evacuated over 100,000 people from Afghanistan since the end of July, including 13,400 during a 24-hour period between Wednesday and Thursday.

NBC News reports that “evacuations are likely to slow considerably by Friday to give the military enough time to effect an orderly withdrawal.”

As the U.S. frantically works to bring U.S. citizens to safety, the security situation around Kabul airport is deteriorating. On Wednesday, the U.S. Embassy in Kabul issued a security alert warning of a terrorist attack and urging Americans not to travel to the Kabul airport. Americans waiting outside the gates were told to “leave immediately.”

An explosion was reported outside the Kabul airport on Wednesday, but details are unclear.

“Every day we’re on the ground is another day we know that ISIS-K is seeking to target the airport and attack both US and allied forces and innocent civilians,” President Biden said on Tuesday.

In addition, it’s clear that the U.S. will not be able to airlift all the Afghans who aided the U.S. war effort before the end of the month. According to The Association of Wartime Allies, at least a quarter million Afghans who may be eligible for expedited American visas remain in Afghanistan.

Blinken tried to reassure that group on Wednesday night.

“Let me be crystal clear about this: There is no deadline on our work to help any remaining American citizens who decide they want to leave to do so, along with the many Afghans who have stood by us over these many years, and want to leave, and have been unable to do so,” Blinken said. “That effort will continue every day past Aug. 31.”

“They will not be forgotten,” Blinken said in response to a question about Afghan allies worried about their safety.

The Taliban claimed they would allow Afghans with proper documentation to access the airport.

“They need passports and visas for the countries they’re going to, and then they can leave by air. If their documents are valid, then we’re not going to ask what they were doing before,” Taliban spokesman Zabihullah Mujahid said on Wednesday.

Those comments are a departure from a press conference Mujahid gave earlier in the week, when he said “We are not in favor of allowing Afghans to leave.”

Since it’s rapid resurgence, the Taliban has pledged to abandon some of the repressive tactics it used in the late 1990s, when it ruled Afghanistan with an iron fist. But international observers are skeptical of those commitments, and the Taliban has confirmed that music will not be allowed in the country and women will be required to have a male chaperone on trips of three days or longer.

For those that remain in Afghanistan, there is much to fear. The New York Times reports:

Adding to the concerns about Afghanistan is its foundering economy, which had been propped up for the past generation by American aid, but is now in free fall. Banks are closed. Cash is growing scarce, and food prices are rising. Fuel is becoming harder to find. Government services have stalled as civil servants avoid work, fearing retribution.