Obama to lead nation in remembering those killed on 9/11

President Barack Obama on Sunday marked the 15th anniversary of the September 11 attacks by calling on Americans to embrace the nation's character as a people drawn from every corner of the world, from every religion and from every background.

While Ground Zero and the nation around it are forever marked but greatly changed since 9/11, the anniversary ceremony itself has become one of the constants in how America remembers the attacks. "The resilience that sustains us", he said on the eve of the 15th anniversary of one of the nation's darkest days.

Americans "don't give into fear", he said, adding, "We will preserve our freedoms and the way of life that makes us a beacon to the world".

This year marks the 15th anniversary of the September 11th terrorist attacks that killed almost 3,000 people at the World Trade Center, Pentagon and on Flight 93.

Al-Qaida leader Osama bin Laden was killed almost a decade later by U.S. forces during a May 2011 raid at his Pakistani bunker.

Following the December shooting rampage in San Bernardino, California for example, Trump called for a temporary ban on the entry to the United States of all Muslims.

Following a moment of silence, and against the backdrop of an American flag that draped the side of the Pentagon where terrorists attacked on September 11, 2001, by flying American Airlines Flight 77 into the western side of the building, the president said the question of how America preserves the legacy of the victims lies in the generation of those who have stepped forward to defend the nation since then.

President Barack Obama at a memorial ceremony at the Pentagon.

Obama urged Americans to stay true to their "ideals" and "reaffirm our character as a nation", saying that was the best way to honor the victims of the attack.

Americans commemorated the 15th anniversary with the recital of the names of the dead, tolling church bells and a tribute in lights at the site where New York City's massive twin towers collapsed.

They believe that rogue elements within the United States government orchestrated or at least encouraged the 9/11 attacks in coordination with Israeli and Saudi Arabian officials to accelerate the U.S. war machine and advance the Zionist agenda. Out of many, we are one.

During a ceremony at 15th anniversary 9/11 attcks at the Pentagon he said, "together, there is nothing we Americans can not overcome". "And we'll keep doing everything in our power to protect our homeland", he said. "Fifteen years ago, America suffered the worst terrorist attack in its history". The first plane struck the north World Trade Center Tower at 8:46 a.m.

A single ring of a bell marked the start of the memorial ceremony in NY.

In a statement, US Secretary of State John Kerry said Americans were not the only ones who fell victim. It's all of us-every American who gets up each day, and lives our lives, carries on.

Trump - a NY real estate mogul - has said he donated construction equipment to the recovery effort and gave $100,000 to the memorial after touring it for the first time earlier this year.