In a televised speech on Thursday evening, US President Joe Biden said the military is in the process of developing "operational plans to strike IS leadership, assets and facilities."

It comes after twin bombing attacks outside Kabul airport killed at least 13 US service members and 95 Afghan civilians. 

The death toll makes it one of the deadliest incidents for American troops for the entire 20-year war in Afghanistan.

The Islamic State's Afghanistan affiliate, known as IS-K claimed responsibility for the terror attacks. It said it had targeted American troops and their Afghan allies in a statement.

What Joe Biden said about the Kabul attacks

In a televised speech on Thursday evening, Biden said: "We will not be deterred by terrorists. We will not let them stop our mission ... We will continue the evacuation."

"We will not forgive. We will not forget. We will hunt you down and make you pay," Biden said, referring to those responsible.

President Biden called the fallen US soldiers "heroes" and said US forces would continue evacuation of US citizens and Afghan allies to meet the August 31 pullout deadline.

He defended his decision to end the US combat mission in the country: "It was time to end a 20-year war."

What were the reactions to the Kabul attack in the US?

US veterans have reacted to the suicide attacks in Kabul, calling the deaths of 85 people including 13 US soldiers "absolutely heartbreaking."

"Everybody that's got someone over there is just sitting there wondering, 'Was it my son, was it my daughter, was it my husband, was it my father?'" Colonel Rob Campbell, US Army (Ret), who served in Afghanistan, told WECT TV in Wilmington, North Carolina.

"It’s absolutely heartbreaking to see what’s going on given the sacrifices that American men and women have done over the last 20-plus years," said former marine raider Chayse Roth, who also served in the war-torn country.

Another ex-serviceman, central-Florida-based Donn Weaver told News 6 that the attacks reminded him of the moment in Sept 2010 when he drove to the airport to collect the body of his son who was killed in Afghanistan.

"My heart goes out to them [relatives of the victims] because there is no way to describe it, the reality doesn’t sink," Weaver said.

"I had hoped it wouldn’t happen, somehow nobody miraculously would be killed getting out, but I knew people would die or be tortured," he said.

Germany sends its condolences

German President Frank-Walter Steinmeier has sent condolences to his US counterpart Joe Biden after the deaths of 13 American soldiers in the Kabul airport attack.

"We mourn with you ... our thoughts are with the families of the brave American soldiers who gave their lives to save the lives of others," he said.

Steinmeier praised the soldiers' courageous efforts, which he said had helped many Germans and thousands of Afghans to be evacuated. He added that Germany stands "firmly at the side of the United States in this difficult hour in the fight against terrorism."

How many people have the US evacuated?

The White House said in a statement Thursday that more than 100,000 people have been evacuated from Afghanistan since the Taliban took over on August 14.

It's estimated that as many as 1,000 Americans are still stranded in Kabul.

Thousands of Afghans who worked with the US military are also stuck in the country, according to the International Rescue Committee.

President Biden has decided to stick with a plan to remove all troops from the country by August 31.

What happened at Kabul airport?

Two suicide bombers and gunmen struck Hamid Karzai International Airport in Kabul on Thursday afternoon. One blast hit the airport's Abbey Gate, while the other targeted a nearby hotel. 

General Kenneth McKenzie, head of US Central Command, said the US airlift in Kabul would continue, adding that the two bombers were "assessed to have been ISIS fighters."

"We continue to execute our number one mission, which is to get as many evacuees and citizens out of Afghanistan," said General McKenzie.

"ISIS will not deter us from accomplishing the mission," he said, adding that US forces were "prepared and ready to defend against" further IS attacks. 

The Taliban also condemned the attacks, saying it was concerned about the "security and protection" of its people. The Islamist militant group is a sworn enemy of IS-K. 

Taliban spokesperson Zabihullah Mujahid also confirmed reports that more blasts had been heard at the airport on Friday morning. But these were controlled explosions carried out by US forces, he said.

rm/rt (Reuters, AP)