Bells tolled across New York City, President Donald Trump spoke at the Pentagon, and moments of silence were observed in Shanksville, Pennsylvania, and across the nation Wednesday as America commemorated the 18th anniversary of the Sept. 11 terror attacks.

Politics also took center stage as Trump targeted the Taliban and a Ground Zero family member took aim at comments made by a Muslim congresswoman.

In New York, the names of the almost 3,000 people who lost their lives were solemnly read at the National September 11 Memorial & Museum. Intermittent moments of silence marked the impact times of the Ground Zero planes, the time when each tower collapsed and the moment when planes struck the Pentagon and a field in Shanksville.

"Eighteen years have not lessened our loss,” Mary Ann Marino said after reading some of the names, including that of her son, firefighter Kenneth Marino.

The first moment of silence was observed at 8:46 a.m. EDT to mark the time when American Airlines Flight 11, en route to Los Angeles from Boston when it was hijacked, slammed into the north face of the World Trade Center's North Tower.

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More moments of silence followed:

• At 9:03 a.m. for United Airlines Flight 175, also bound for Los Angeles from Boston, when it crashed into the south face of the World Trade Center's South Tower.

• At 9:37 a.m. for American Airlines Flight 77, scheduled to fly from Washington to Los Angeles when it hit the Pentagon.

• At 10:03 a.m. for Flight 93, flying from Newark, New Jersey, to San Francisco when it slammed into a western Pennsylvania field.

The World Trade Center's South Tower collapsed at 9:59 a.m.; the North Tower fell 29 minutes later.

The New York ceremony was open only to family members, but the event was streamed live. The memorial will open to the public later in the day.

Nicholas Haros Jr., whose mother, Frances, died in the World Trade Center, challenged a statement this summer from Rep. Ilhan Omar, D-Minn., that "some people did something and that all of us were starting to lose access" to civil liberties. Haros wore a black T-shirt with the words "Some people did something" as he read the names of the dead.

"Our constitutional freedoms were attacked, and our nation’s founding on Judeo-Christian values was attacked. That’s what ‘some people’ did. Got that now?” Haros said.

In Shanksville, Vice President Mike Pence lauded heroes from United Airlines Flight 93. The Memorial Plaza is near the site where Flight 93 crashed into a field after passengers fought with hijackers intent on crashing into the U.S. Capitol.

The memory of those who died is “carved into the hearts and memories of the American people," Pence said. The names of the 40 passengers and crew were read, and the Bells of Remembrance were rung. A wreath was placed at the Wall of Names at the site.

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Trump led a brief remembrance on the South Lawn of the White House, joined by hundreds of guests, including 9/11 survivors and family members and current and former law enforcement personnel. He then spoke at a ceremony at the Pentagon, where 184 people were killed 18 years ago.

"Today the nation honors and mourns nearly 3,000 lives that were stolen from us," Trump said. He recounted going to Ground Zero after the planes hit.

"We are united with you in grief," he said. "We offer you all that we have: our unwavering loyalty, our undying devotion, our eternal pledge that your loved ones will never, ever be forgotten."

Trump blamed the Taliban for the cancellation of peace talks to try to end the war that started in Afghanistan shortly after the Sept. 11 attacks. He said U.S. forces have "hit them" harder than ever.

"And if for any reason they ever come back to our country, we will go wherever they are and use power the likes of which the U.S. has never used before," Trump said.

Cities and towns across the nation marked the anniversary. In Michigan, an anti-Muslim event was canceled amid condemnation from politicians and organizations.

Bloomfield Hills Baptist Church announced in a one-sentence email Monday evening that it canceled a two-day event called "9/11 forgotten? Is Michigan surrendering to Islam?" that had been scheduled for Wednesday and Thursday. The event was set to host two speakers addressing topics such as "How the interfaith movement is sabotaging America and the church" and "How Islam is destroying America from within."

Contributing: David Jackson and Jeanine Santucci, USA TODAY; Emma Keith, Detroit Free Press; The Associated Press