America marks 25th anniversary of 9/11 attacks

The United States has marked the 25th anniversary of the September 11 attacks, with current and former political leaders gathering to honour the nearly 3,000 people killed when hijacked aircraft crashed into the World Trade Center, the Pentagon and a field in Pennsylvania.

President Donald Trump led a commemorative ceremony at the Pentagon, while Vice-President JD Vance joined thousands of mourners at the World Trade Center site in New York.

All four living former US presidents - George W Bush, Joe Biden, Barack Obama and Bill Clinton - attended the New York ceremony alongside former first ladies.

Moments of silence were observed at the times the four hijacked aircraft crashed and when the World Trade Center towers collapsed. The names of those killed in the attacks were read aloud during a ceremony that lasted almost four hours.

On Friday evening, the annual Tribute in Light illuminated the Manhattan skyline with two powerful beams representing the destroyed towers. Landmarks across New York state were also lit in blue to commemorate the anniversary.

Bush, who was president when the attacks occurred, joined Biden, Obama and Clinton at the World Trade Center memorial.

At the Pentagon, Trump attended a ceremony with members of his cabinet and Condoleezza Rice, who served as national security adviser under Bush during the attacks.

"Today we renew the sacred oath that we first swore in their names a quarter of a century ago," Trump said. "We will never, ever forget. That's why we fight today."

Trump also connected the US-led "war on terror" that followed the attacks with his administration's current confrontation with Iran, telling those gathered that the Islamic Republic would never be allowed to obtain a nuclear weapon.

A separate commemoration was held in Shanksville, Pennsylvania, where United Airlines Flight 93 crashed after passengers attempted to overpower the hijackers. The aircraft was believed to have been heading towards a target in Washington before it came down.

The anniversary ceremonies also recognised the thousands of people who have died in the years since the attacks from illnesses linked to exposure to dust and smoke following the collapse of the World Trade Center.

A seventh bell was rung during this year's New York ceremony to honour those later deaths, alongside the traditional bells marking the key moments of the attacks.

US health officials say deaths from illnesses associated with exposure to the World Trade Center site have now exceeded three times the number of people killed directly on September 11, 2001.

During the New York ceremony, Terry Strada, whose husband Tom was killed in the attacks, criticised what she described as the failure of US authorities to hold Saudi Arabia accountable for its alleged links to the attacks.

"You are missed more with each year that passes," Strada said of her husband.

She also questioned why, after 25 years, families were still seeking accountability over Saudi Arabia's alleged role.

Strada, who chairs 9/11 Families United, received applause from those attending the ceremony.

Nineteen hijackers carried out the attacks, with the majority coming from Saudi Arabia. The operation was planned by al-Qaeda founder Osama bin Laden, who was born into a prominent Saudi family.

Saudi authorities have consistently denied involvement in the attacks. The 9/11 Commission, which investigated the attacks, reported in 2004 that it had found no evidence that the Saudi government as an institution or senior Saudi officials individually had funded al-Qaeda.

Twenty-five years on, the commemorations remain a solemn reminder of the scale of the attacks, their lasting impact on victims' families and the profound changes they brought to US foreign policy and national security.