The MTA should be focusing less on how it will pay for its proposed $32 billion capital program, and more on convincing politicians, and the public, of its importance, the agency's chief said Thursday.

Metropolitan Transportation Authority chairman and chief executive Thomas Prendergast made his case for the importance of all the projects in the agency's newly proposed capital program at a Manhattan meeting of the General Contractors Association.

The program, which includes projects to maintain, expand and improve the MTA system through 2019, has a price tag of $32 billion, but the MTA says it can only come up with the money to pay about $17 billion of that. In the past, federal and state governments have helped fund the MTA's capital programs, including by creating new revenue streams for the agency, like the state payroll mobility tax, adopted in 2010.

After it was proposed in September, Gov. Andrew M. Cuomo called the $32 billion plan "bloated" and said a more "realistic number" must be reached.

Prendergast said his mission was to "establish the need first, and then talk about finances."

"We need to have a dialogue on that so that we get a strong consensus behind the fact that they think the makeup of the program is right . . . then we go after the funding," Prendergast said.

About two-thirds of the proposed capital budget would go to maintaining the existing MTA system, which Prendergast has valued at $1 trillion. The other third would be split between efforts to enhance the system, through projects like positive train control crash prevention technology on the Long Island Rail Road and Metro-North, and expand it, including by fully funding the East Side Access project to link the LIRR to Grand Central Terminal.

Prendergast did not offer specific ideas to generate new revenue for the agency, other than to say a rollback of the payroll mobility tax -- as sought by many Republican lawmakers -- "would be a concern" to the MTA.

But Carol Kellerman, president of the nonprofit Citizens Budget Commission, brought up several ways to raise money for the MTA's capital needs, including larger New York City subsidies, tolls on now-free East River bridges and tunnels, higher DMV fees and an MTA fare hike steeper than the 4 percent increase planned for next year.

Kellerman, who took part in a panel discussion following Prendergast's remarks, said that while such proposals are politically unpopular, there's no way around having transit riders, drivers, and taxpayers pay more.

"It's going to come from us. It's just not a free system," Kellerman said.