President Obama called on Congress Friday to approve $21 billion in new spending to repair America’s ports, roads and bridges, with the administration saying it will explain later how to pay for the programs.

“Building better roads and bridges and schools, that’s not a partisan idea,” Mr. Obama said after a tour at the port of Miami. “I know that members of Congress are happy to welcome projects like this in their district — I know because I’ve seen them at the ribbon-cuttings.”

The president outlined three initiatives, including a $10 billion “infrastructure bank” that would leverage private capital to fund various projects nationwide. He’s been proposing the idea for years, but Republican lawmakers haven’t accepted it.

After the president revealed some of these same proposals in his State of the Union address, Speaker John A. Boehner said he couldn’t support them without knowing where the resources would come from to fund the projects.

“It’s easy to go out there and be Santa Claus and talk about all the things you want to give away, but at some point somebody has to pay the bill,” Mr. Boehner said at the time.

Mr. Obama insisted the proposals are needed to boost the economy, which is stuck in low gear.

“We can’t afford Washington politics to stand in the way of America’s progress,” he said. “Ultimately, Congress has to fund these projects. It’ll put people back to work, and it will grow our economy in the process.”