Promising to put aside divisive presidential politics, senators McCain and Obama will be in New York today for the seventh anniversary of the attacks of September 11, 2001, appearing together at Columbia University for a forum on public service.

The campaigns have been trading sharp personal attacks in recent days, with Mr. Obama making headlines for saying, “You can put lipstick on a pig, but it’s still a pig,” when talking about Mr. McCain’s claim that he will bring change to Washington. The McCain campaign claimed the line was an attack on Mr. McCain’s running mate, Governor Palin, who said during the Republican Convention that the only difference between a hockey mom and a pit bull is lipstick.

The candidates are expected to visit ground zero, but Mayor Bloomberg said yesterday that they would not be attending the official anniversary ceremony in the morning, and said he wants to make sure it doesn’t turn into a political event.

“We are honored to have both the presidential candidates want to come here and together express their remorse for what happened and their confidence in the future, but it can’t degenerate into a spectacle, so we will try to find that balance and at the same time provide security,” he said.

Mr. Obama is also scheduled to have a private lunch meeting with President Clinton at his office.