The U.S. Central Command announced Monday that the withdrawal of U.S. troops from Afghanistan has been completed, 20 years after a U.S.-led invasion of the country. 
  
"I'm here to announce the completion of our withdrawal from Afghanistan and the end of the mission to evacuate American citizens, third country nationals and vulnerable Afghans," Kenneth McKenzie, commander of U.S. Central Command, announced during a news conference held by the Department of Defense. 
  
"The last C-17 lifted off from Hamid Karzai International Airport on August 30, this afternoon, at 3:29 p.m. East coast time, and the last manned aircraft is now clearing the space above Afghanistan," McKenzie said. 

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Live updates: U.S. completes withdrawal from Afghanistan

Afghanistan in transition

The withdrawal came after the fraught final days of a frantic mission to evacuate tens of thousands of Americans and Afghans who had helped the U.S.-led war effort – and which left scores of Afghans and 13 U.S. troops dead in a suicide bombing attack last week.  

The evacuation flights have taken more than 123,000 people out of Kabul airport, according to McKenzie, but he admitted not everyone who wanted to leave was able to, and that the "diplomatic mission" to allow others to leave will continue.

"There's a lot of heartbreak associated with this departure. We did not get everybody out that we wanted to get out," he said. "But I think if we'd stayed another 10 days, we wouldn't have gotten everybody out." 

The withdrawal came before August 31, the deadline set by U.S. President Joe Biden to call time on America's longest war – one that ultimately claimed the lives of more than 2,400 U.S. service members. Biden said he would address the nation on Tuesday in Washington. 

U.S. Secretary of State Antony Blinken said on Monday that the country embarked on a "new" chapter regarding Afghanistan and shifted its diplomatic operations to Qatar. 

"As of today, we've suspended our diplomatic presence in Kabul and transferred our operations to Doha, Qatar," Blinken said. 

He said less than 200 Americans were believed to have remained in Afghanistan and vowed to keep up "relentless" efforts to help Americans, Afghans and others leave the country if they choose to do so. 

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Chart of the Day: The Afghanistan exodus by the numbers

Return of Taliban and the future of Afghanistan

Celebratory gunfire echoed across Kabul as Taliban fighters took control of the airport before dawn on Tuesday. The group welcomed the U.S. withdrawal, hailing the "complete independence" of Afghanistan.  

"In this way, our country became completely free and independent," Taliban spokesman Zabihullah Mujahid wrote on Twitter. 

"Congratulations to Afghanistan ... this victory belongs to us all," Mujahid told reporters hours later from the runway of the airport, describing the Taliban's victory as a "lesson for other invaders." 

"We want to have good relations with the U.S. and the world. We welcome good diplomatic relations with them all," he added. 

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The 20-year war in Afghanistan: What happened and what's next?

Ambassador: China has evacuated most nationals from Afghanistan

U.S.-led foreign forces invaded Afghanistan in 2001 and overthrew the then Taliban administration. The group took control of Kabul again on August 15 after a blitz against West-backed government forces amid the withdrawal of foreign troops. 

The U.S. had spent approximately $2.26 trillion on the war in Afghanistan over the past two decades, or an average of over $300 million per day, according to the Costs of War Project run by the Watson Institute of Brown University. 

As of April, an estimated 241,000 people had lost their lives as a direct result of the war in Afghanistan, including tens of thousands of civilians, the project showed. 

A recent poll by The Associated Press-NORC Center for Public Affairs Research said roughly two-thirds of Americans did not think the war was worth fighting. 

In a global survey conducted by the CGTN Think Tank on social media platforms, 84.6 percent of the respondents believe the U.S. war in Afghanistan has failed. 

Yue Xiaoyong, the special envoy for Afghan affairs of the Chinese Foreign Ministry, said in mid-August that the situation in Afghanistan was a military, political and reputational "fiasco" for the United States. 

Geng Shuang, China's deputy permanent representative to the United Nations, said at a Security Council emergency meeting on Monday that relevant countries can realize that withdrawal is not the end of responsibility, but the beginning of reflection and correction.  

Geng urged relevant countries to learn from the lesson and earnestly respect the sovereignty, independence and territorial integrity of Afghanistan, and the right of the Afghan people to independently determine their own future and destiny. 

(With input from agencies)

(Cover: Taliban fighters celebrate before storming into Hamid Karzai International Airport, wielding American supplied weapons, equipment and uniforms after the U.S. military completed their withdrawal, in Kabul, Afghanistan, August 31, 2021. /Getty)