Ceremonies will be held in New York City, Virginia and Pennsylvania.
NEW YORK -- Friday marks 25 years since the Sept. 11, 2001, terror attacks, which claimed the lives of 2,977 people at the World Trade Center, the Pentagon and in Shanksville, Pennsylvania.
Another 9,000 people have died from 9/11-related illnesses over the last 25 years.
Victims' families, first responders and politicians gathered on Friday for annual remembrance ceremonies as Americans across the country pause to remember and reflect.
"9/11 Tribute in Light: Live from Lower Manhattan," a one-hour ABC News multiplatform live special, premieres on Friday, Sept. 11, at 8 p.m. EDT on this ABC station, Disney+, Hulu, National Geographic and ABC News Live.
Hundreds of people gathered in Shanksville, Pennsylvania, to mark the 25th anniversary of United Flight 93's crash.
The family members of the 40 passengers and crew who were killed read their names, accompanied by bells.
The color guard folded a U.S. flag and placed it on a giant rock near the edge of a grove of hemlocks. That rock is where some of the very last pieces of Flight 93 came to rest.
Cheers erupted during the Manhattan ceremony after Terry Strada, who lost her husband Tom on 9/11, condemned Saudi Arabia for its alleged role in the terrorist attacks.
"You are missed more with every day that passes, but how can it be 25 years and we have no justice for the role that Saudi Arabia played in your murder," she said of her husband.
As ABC News reported last week, a coalition of victims' families are suing the Saudi government over its alleged role and have continued to pursue evidence they say points to deep Saudi complicity. The Saudis deny that claim and are fighting the suit in court.
The Saudis have repeatedly denied having any role in facilitating the attacks and replied in court that they remain "an ally of the United States (and) a sworn enemy of Al Qaeda."
White House spokesperson Anna Kelly told ABC News last week that, "President Trump is leading the most transparent administration in history, and his team is working diligently to identify records that are responsive to these families' request."
Strada called out "administration after administration" for choosing "to protect the Saudis instead of standing with the 9/11 families."
"President Trump can still change that. Tell the Saudis to stop lying," she said.
Strada finished her speech by talking directly to Vice President JD Vance, who was in attendance, and told him to carry that message to the president.
"Stand with survivors, stand with Americans," she said. "As my husband Tom would have said, that is always the right thing to do. God bless all of us. God bless America."
The sixth moment of silence was held at 10:28 a.m., to mark the moment the World Trade Center's North Tower collapsed, nearly 30 minutes after the South Tower fell.
The president addressed the crowd at the 9/11 ceremony at the Pentagon.
Trump reflected on the horrors of the attack and the thousands killed in on 9/11, but noted the strong response from America against its enemies.
"That's why we fight today," he said. "We do not have a choice, we can only have victory."
