The US presidential rivals, Barack Obama and John McCain have said they will appear together on the anniversary of the 11 September 2001 attacks.
The senators said they would take part in the commemorations in New York - the site of two of the attacks.
The two candidates said they would put aside politics to honour the memory of the nearly 3,000 people who died.
Hijacked planes were crashed into New York's Twin Towers, the Pentagon in Washington and a field in Pennsylvania.
"All of us came together on 9/11 - not as Democrats or Republicans - but as Americans," the joint statement said.
"In smoke-filled corridors and on the steps of the Capitol; at blood banks and at vigils - we were united as one American family.
"On Thursday, we will put aside politics and come together to renew that unity, to honour the memory of each and every American who died, and to grieve with the families and friends who lost loved ones."
The event at Ground Zero - site of the collapsed Twin Towers of the World Trade Center - will mark the first time Mr McCain and Mr Obama have been together since they were formally nominated as presidential candidates at their parties' just-completed national conventions.
The two agreed not to run television ads critical of each other on Thursday and Mr McCain's campaign team said they would not run any ads.