By Douglas Feiden | The Dailey News

Mayor Bloomberg is pinning much of the blame for an impasse in talks over thefuture of Ground Zero on the Port Authority. In a joint statement, the mayor and Assembly Speaker Sheldon Silver suggest that the bistate agency's goals differ from the interests of the city and thenation.

"We are disappointed that we have yet to reach agreement to address the latest impasse at the World Trade Center site," the two politicians wrote Tuesday.

"We fundamentally believe there are opportunities to find mutually agreeable and responsible terms ... that allow continued progress at Ground Zero."

At issue are the questions of what will be built at the 16-acre site and who will pay for it in a time of shrinking public budgets and private financing.

Behind the scenes, insiders told of frustration boiling over as Bloomberg and Silver, the powerful Democrat who represents lower Manhattan, pushed a reluctant Port Authority to guarantee more financing to developer Larry Silverstein.

Hanging in the balance is Bloomberg's command of his bully pulpit in an election year: It was a month ago that he summoned the PA and Silverstein to Gracie Mansion to thrash out a deal over financing for three office towers on Church St. So far, there has been no progress.

Silverstein is seeking financing for two skyscrapers, but the Port Authority wants to back only one tower - and the two sides are at least $2 billion apart.

"We will continue to negotiate in good faith," a Port Authority spokesman said. "We are working with all parties to advance the private development in a way that protects public resources for the people of this region."