'Never, ever forget' - America marks 25th anniversary of 9/11 attacks

Twenty-five years after 9/11, US presidents past and present have commemorated the lives lost when hijacked planes slammed into the World Trade Center, the Pentagon and a Pennsylvania field.

President Donald Trump led a Pentagon ceremony, while US Vice-President JD Vance attended a memorial at the site of the World Trade Center in New York, along with all four living former US presidents and first ladies.

Moments of silence were held to mark the timings of the attacks and the names of nearly 3,000 people who died were read out.

Two beams of light illuminated the Manhattan sky for a Tribute in Light on Friday evening, as other landmarks in the state lit up in blue in commemoration.

George W Bush, who was president at the time of the attacks, was joined by former Presidents Joe Biden, Barack Obama and Bill Clinton at Friday's ceremony at the World Trade Center site.

At the Pentagon, President Trump attended a commemoration alongside cabinet secretaries and Condoleezza Rice, who was national security adviser on 9/11.

"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."

He sought to link the "war on terror" that followed 9/11, which sparked years of US involvement in Middle East wars, with his current conflict in Iran.