The 11th annual remembrance of the 9/11 tragedy was low-key in the U.S.

Sparing a moment from an intense presidential election campaign that has gripped the nation for months, the United States on Tuesday marked a low-key eleventh anniversary of the September 11, 2001 terrorist attacks that killed thousands.

President Barack Obama laid a wreath at the Pentagon in honour of the victims of the deadly attacks, and said the experience made the US “even stronger”.

“Our country is safer, and our people are resilient,” Mr. Obama said at a ceremony at the White House. “The true legacy of 9/11 will not be one of fear or hate or division. It will be a safer world, a stronger nation, and a people more united than ever before.”

The US blamed the terrorist network, Al Qaeda, for the killings culminating in two running conflicts: in Afghanistan where the key operatives of the group were shielded by the ruling Taliban before 2001 and in the Saddam Hussein-led Iraq accused of sponsoring terrorism.

The US Navy Seal killed Osama Bin Laden, the alleged mastermind of the attacks and leader of Al Qaeda in an early morning raid in Pakistan on May 2, 2011.

At least 1,987 U.S. troops have died in Afghanistan and 4,475 in Iraq, according to the Pentagon.

Each year, relatives of the nearly 3,000 people killed when hijacked airliners smashed into New York’s World Trade Center gather at Ground Zero to read the names of the dead.

The ceremony took place on the grounds of the 9/11 Memorial between the two huge black fountains that mark the footprints of the old Twin Towers.

Mr. Obama and his wife Michelle observed the anniversary with a moment of silence outside the White House, then a visit to the Pentagon memorial.

Allied military forces marked the anniversary at a short ceremony at NATO’s headquarters in Kabul, Afghanistan with a tribute to more than 3,000 foreign troops killed in the decade-long war.

“Eleven years on from that day, there should be no doubt that our dedication to this commitment, that commitment that was seared into our souls that day so long ago, remains strong and unshaken,” Marine Gen. John Allen, the top commander of U.S. and coalition troops was quoted as saying.

In New York, relatives read out the names of those that died, and for the first time, politicians did not address the event.