President Obama and New York Police Department officer Stephanie Moses bow their heads at a wreath laying ceremony at Ground Zero.

By: Associated Press via NYDailyNews

It could be the only day before Nov. 6 without explicit partisan rancor.

Both President Barack Obama and Republican challenger Mitt Romney plan to take down their negative ads in honor of the 11th anniversary of the 9/11 terrorist attacks. Neither planned to appear at overtly political events, although Election Day is never far from their agendas.

Obama has scheduled a moment of silence at the White House and a trip to the Pentagon, the target of one of four planes al-Qaida hijacked 11 years ago. Romney, meanwhile, is set to address the National Guard, whose members deployed as part of the U.S. response to the attacks.

“On this most somber day, those who would attack us should know that we are united, one nation under God, in our determination to stop them and to stand tall for peace and freedom at home and across the world,” Romney said in a statement released before his speech.

Vice President Joe Biden is expected to attend a memorial service at Shanksville, Pa., where one of the hijacked airliners crashed. Biden grew up in Scranton, Pa.

Romney’s running mate, Rep. Paul Ryan of Wisconsin, plans to spend the day in his home state and hasn’t scheduled any public events. Ryan said in his own statement that Sept. 11 is a time to pay tribute to those who quietly work to prevent attacks and to those in the military “who have sacrificed so much, including their lives, for the same end.”

On behalf of the Obama campaign, former President Bill Clinton is set to attend an evening rally at Florida International University in Miami.

At the White House on Monday, spokesman Jay Carney said Obama planned to remember those who lost their lives in 2001 and those who served in the two wars that followed.

“He certainly hopes and knows that Americans across the country will take a moment to reflect upon the events of Sept. 11, 2001, and all that our country has been through together since then,” Carney said. “And especially, I think, take that moment to remember the victims and their families from that terrible event.”

The attack killed almost 3,000 in the United States and was followed by wars in Afghanistan and Iraq. At least 1,987 U.S. troops have died in the Afghanistan war and 4,475 in Iraq, according to the Pentagon.

Perhaps the most obvious signal that the presidential campaign is on hold is that negative ads will be taken off the air, following precedent.

Obama and his allies have spent $188 million on TV commercials, according to information from media buyers provided to The Associated Press. Romney and the independent groups backing him have spent $245 million on ads through the end of August.