The US State Department has warned all its citizens at the gates outside the Hamid Karzai International Airport in Kabul to leave “immediately” due to threats.

US citizens who are at the Abbey Gate, East Gate, or North Gate now should leave immediately, a security alert from the US Embassy in Kabul said.

“Because of the security threats outside the gates of Kabul airport, we are advising US citizens to avoid traveling to the airport and to avoid airport gates at this time unless you receive individual instructions from a US government representative to do so,” the US Embassy said.

The Taliban have bolstered their access and control around the Kabul airport, choking it at the time of a massive evacuation process, the Pentagon said in a statement.

“We are going to do everything that we can to provide safe evacuation for Americans, our Afghan allies, partners, and Afghans who might be targeted because of their association with the United States,” President Joe Biden informed on social media platform Twitter.

US Secretary of State Antony Blinken reaffirmed that efforts are underway to ascertain whether regional countries can play an active role in keeping the Kabul airport to ensure repatriation missions.

“There are active efforts underway on the part of regional countries to see whether they can play a role in keeping the airport open once our military mission leaves or, as necessary, reopening it if it closes for some period of time. The Taliban have made clear that they have a strong interest in having a functioning airport. We and rest of the international community have a strong interest in that, primarily for the purpose of making sure that anyone who wants to leave can leave past August 31 using the airport… With regard to our own potential presence going forward after the deadline, we are looking at a number of options,” Blinken said.

The Kabul airport is the only access point for the international community to connect with Afghanistan, a land-locked nation.

“The Taliban have bolstered their own security at their checkpoints and have gotten involved in crowd control…every day is a different day, and yesterday we estimated that crowds were about half the size they had been the previous days. We still haven’t seen them rise to the level they were in the early days of this. But yes, part of the reason is certainly that the Taliban have strengthened their measures of access and control around the field,” Pentagon Press Secretary John Kirby told reporters on Wednesday.