The US on Monday remembered the September 11, 2001 attacks, 22 years after hijackers seized control of three passenger jets and crashed them into the twin towers of New York's World Trade Centre and the Pentagon, while a fourth plane came down in rural Pennsylvania.
The decision to hold the event in Alaska, instead of Washington or New York, was a departure from what has been presidential custom, and right-wing critics condemned him for being so far from the East Coast. Vice President Kamala Harris attended a ceremony at the 9/11 Memorial in New York, built at the site of the collapsed World Trade Centre.
The attacks killed more than 3,000 people and prompted then-president George W Bush to launch a “global war on terror” that included a military assault on Afghanistan to find Al Qaeda leader Osama bin Laden.
“The memory of those who perished on 9/11 reminds us of why we must continue to fight against those who commit acts of terrorism,” US Secretary of State Antony Blinken said in a statement.
“In the years since, we have stood side by side with partners from around the world to end the scourge of terrorism and ensure terrorists are held accountable for their crimes. The United States will continue to defend our homeland, our people and our allies.”
Bin Laden eluded capture until he was killed in a US raid on his Pakistan compound in 2011 ordered by then-president Barack Obama.
The 9/11 attacks were the worst on US soil since the 1941 Japanese bombing of Pearl Harbour, Hawaii, when 2,400 people were killed. That event brought America into the Second World War.