Joe Biden and Republican Vice Presidential candidate Mike Pence start the day in New York City at the 9/11 memorial museum at Ground Zero.
Biden and President Donald Trump will both visit the Shanksville, Pennsylvania memorial site.
Kamala Harris is to speak at a 9/11 remembrance ceremony in Fairfax, Virginia.
Speaker of the House Nancy Pelosi will preside over a moment of silence at the US Capitol building.
Here are the latest updates:
Friday, September 11 10:03 ET – Moment of silence observed at 9/11 Remembrance Ceremony for crash of Flight 93 in Shanksville, Pennsylvania
Participants in the national September 11 Remembrance Ceremony at Ground Zero in New York City observed a moment of silence at the approximate time of the crash of United Airlines Flight 93 in near Shanksville, Pennsylvania.
President Donald Trump is in Pennsylvania and preparing to speak at the site of the crash, now a national park, to honour the 40 passengers and crew who lost their lives. The plane crashed after four hijackers flying toward Washington, DC, were overcome by passengers who tried to regain control.
09:30 ET –
Biden backs Trump
s push to draw down troops from Iraq and Afghanistan
Democratic presidential nominee Joe Biden said he supports President Donald Trump’s push to withdraw US troops from Iraq and Afghanistan, though not completely.
“These ‘forever wars’ have to end. I support drawing down the troops,” Biden told the newspaper Stars and Stripes. “But here’s the problem, we still have to worry about terrorism and [the Islamic State].”
“I think we need special ops capacity to coordinate with our allies,” Biden said, adding that a maximum of “1,500 to 2,000” should remain.
08:53 ET – Second ceremony, attended by Mike and Karen Pence, taking place
A second independent ceremony not affiliated with the official ceremony takes place at Zuccotti Park near the 9/11 Memorial & Museum, an event organized by the Tunnel to Towers Foundation attended by Vice President Mike Pence and his wife, Karen Pence, and acting secretary of Homeland Security Chad Wolf.
Karen Pence read a passage from Ecclesiastes 3: “There is a time for everything, and a season for every activity under the heavens.”
The vice president followed her with a brief reading from the Bible. “For the families and loved ones and friends they left behind, I pray these ancient words will comfort your hearts, and ours”, he said before reciting Psalm 23, which begins with “The Lord is my shepherd”.
08:45 ET – Ground Zero ceremony begins
A military guard carries the flag that flew at Ground Zero around the site, Vice President Mike Pence stood not far from Joe and Jill Biden, who were next to Governor Andrew Cuomo, for the moment of silence at the site. Soon after, recordings of the names of the dead were played and a bell rang out for each one.
Everyone in the crowd appears to be masked, some are holding bouquets of flowers, many police, military and firefighters stand at attention.
08:10 ET – Joe Biden has landed at Newark Liberty Airport en route to Ground Zero
Before leaving for New York, Biden said he did not plan to make news, or hold any press conferences calling it “a solemn day”.
“I’m not going to talk about anything other than 9/11. We took all our advertising down. It’s a solemn day. That’s how we’re going to keep it.”
The 9/11 commemoration ceremony Biden and his wife will attend will be different from previous years with the names of those killed not being read out live, but pre-recorded because of coronavirus restrictions.
Participants are required to wear face coverings and practice social distancing on the Memorial plaza where the World Trade Center towers once stood.
Hello and welcome to Al Jazeera’s continuing coverage of the US elections. This is William Roberts.
Read all the updates from yesterday (September 10) here.