The U.S. Embassy in Kabul has issued a security alert Wednesday evening advising Americans to avoid traveling to the airport in Afghanistan's capital city.

The said security alert issued by the embassy encouraged Americans at the airport gates - Abbey Gate, East Gate, or North Gate - to "leave immediately" due to the security threats outside Kabul airport.

The U.S. Embassy in Kabul advised Americans to be aware of their surroundings at all times, especially in large crowds, and follow the instructions of local authorities.

The embassy also advised Americans to have contingency plans in case of emergencies, monitor local media, enroll in the Smart Traveler Enrollment Program (STEP) to receive alerts, and follow the State Department on social media. It was still unclear what prompted the advisory.

READ NEXT: Fox News Host, Rachel Campos-Duffy Slams Jill Biden for Letting 'Mentally Frail' Husband Joe Biden, Run as President

U.S. Secretary of State Antony Blinken: Up to 1,500 Americans Still in Afghanistan

On Wednesday, U.S. Secretary of State Antony Blinken said there could be up to 1,500 Americans who are still in Afghanistan and attempting to evacuate.

Blinken blamed the Americans still in the South Asian country for not leaving fast enough after being warned earlier this year to leave the country as soon as possible.

According to Blinken, the U.S. has been in "direct contact" with around 500 confirmed U.S. citizens and was provided detailed instructions on how to get to the airport safely.

The secretary of state noted that some Americans might no longer be in Afghanistan, while some claimed to be Americans but turned out not. He said they will continue to identify the status and plans of the people stuck in Afghanistan in the coming days. 

White House Says Joe Biden's Evacuation Efforts in Afghanistan - A 'Success'

On Tuesday, White House press secretary Jen Psaki lauded the evacuation efforts of President Joe Biden in Afghanistan. Psaki said the evacuation efforts were "anything but a success."

She called the ongoing evacuation in Afghanistan to be the "biggest airlift in U.S. history." Psaki said that American citizens, as well as Afghan partners, were pulled out from the country.

To date, more than 70,000 people have been removed from Afghanistan. Joe Biden on Tuesday said the U.S. has already evacuated at least 75,900 people from Afghanistan.

Meanwhile, Pentagon press secretary John Kirby noted that "several thousand" Americans have already been evacuated, but he failed to give a more specific figure.

On Tuesday, Joe Biden told other G7 leaders that the U.S. is on pace to complete the pullout from Afghanistan by August 31. But Psaki said the president already asked the Pentagon and the State Department "for contingency plans" to adjust the timeline if it becomes necessary.

The Taliban earlier warned the U.S. that there would be consequences if the evacuation and withdrawal of troops in Afghanistan would go beyond the August 31 deadline.

Taliban spokesperson Dr. Suhail Shaheen has called the withdrawal deadline "red line." Shaheen noted that if the U.S. extends it, "that means they are extending occupation while there is no need for that."

"It will create mistrust between us. If they are intent on continuing the occupation, it will provoke a reaction," Shaheen said.

READ MORE: Angelina Jolie Joins Instagram, Posts Heartfelt Letter Sent to Her by an Afghan Girl

This article is owned by Latin Post

Written By: Joshua Summers

WATCH: Security Concerns at Kabul Airport as Americans and Afghans try to Evacuate - From Good Morning America