Trump, the Republican presidential nominee, is expected to visit Arlington National Cemetery to pay his respects to the service members killed in the bombing outside the Kabul airport. Trump will then go to Michigan to address the National Guard Association of the United States conference.

Monday marks three years since the Aug. 26, 2021, suicide bombing at Hamid Karzai International Airport, which killed 13 American service members and more than 100 Afghans. The Islamic State group claimed responsibility for the attack.

On his Truth Social site Monday, Trump called the withdrawal "the most EMBARRASSING moment in the history of our Country. Gross Incompetence - 13 DEAD American soldiers, hundreds of people wounded and dead."

"You don't take our soldiers out first, you take them out LAST, when all else is successfully done," he said in the post.

Since President Joe Biden ended his reelection bid, Trump has been zeroing in on Harris, now the Democratic presidential nominee, and her roles in foreign policy decisions. He has specifically highlighted the vice president's statements that she was the last person in the room before Biden made the decision on Afghanistan.

"She bragged that she would be the last person in the room, and she was. She was the last person in the room with Biden when the two of them decided to pull the troops out of Afghanistan," he said last week in a North Carolina rally. "She had the final vote. She had the final say, and she was all for it."

In a statement marking the anniversary of the Kabul airport attack, Harris said she mourns the 13 U.S. service members who were killed. "My prayers are with their families and loved ones. My heart breaks for their pain and their loss," she said.

Harris said she honors and remembers all Americans who served in Afghanistan.

"As I have said, President Biden made the courageous and right decision to end America's longest war. Over the past three years, our Administration has demonstrated we can still eliminate terrorists, including the leaders of al-Qaeda and ISIS, without troops deployed into combat zones," she said. "I will never hesitate to take whatever action necessary to counter terrorist threats and protect the American people."

The relatives of some of the 13 American service members who were killed appeared on stage at the Republican National Convention last month, saying Biden had never publicly named their loved ones. The display was an implicit response to allegations that Trump doesn't respect veterans and had previously referred to slain World War II soldiers as suckers and losers -- accusations denied by Trump.

In a statement Monday on the Kabul attack anniversary, Biden said the 13 Americans who died were "patriots in the highest sense" who "embodied the very best of who we are as a nation: brave, committed, selfless."

"Ever since I became Vice President, I carried a card with me every day that listed the exact number of American service members who were killed in Iraq and Afghanistan--including Taylor, Johanny, Nicole, Hunter, Daegan, Humberto, David, Jared, Rylee, Dylan, Kareem, Maxton, and Ryan," Biden said.

Under Trump, the United States signed a peace agreement with the Taliban that was aimed at ending America's longest war and bringing U.S. troops home. Biden later pointed to that agreement as he sought to deflect blame for the Taliban overrunning Afghanistan, saying it bound him to withdraw troops and set the stage for the chaos that engulfed the country.

A Biden administration review of the withdrawal acknowledged that the evacuation of Americans and allies from Afghanistan should have started sooner, but attributed the delays to the Afghan government and military, and to U.S. military and intelligence community assessments.

The top two U.S. generals who oversaw the evacuation said the administration inadequately planned for the withdrawal. The nation's top-ranking military officer at the time, then-Joint Chiefs Chairman Gen. Mark Milley, told lawmakers earlier this year he had urged Biden to keep a residual force of 2,500 forces to give backup. Instead, Biden decided to keep a much smaller force of 650 that would be limited to securing the U.S. embassy.