BOSTON (AP) — Hillary Rodham Clinton is calling for $275 billion in new federal spending on infrastructure, kicking off what her campaign says will be a month-long focus on job creation.

The Democratic presidential candidate on Sunday promised to rebuild "ladders of opportunity" to help more Americans achieve a "middle-class lifestyle."

Clinton's campaign said she would allocate $250 billion to direct investment by the federal government in crumbling roads, bridges, transit and airports. An additional $25 billion would fund a national infrastructure bank, an idea that has been blocked repeatedly by congressional Republicans.

The new proposals are the most expensive portion of Clinton's economic agenda, which her campaign will be rolling out in the coming weeks.

Clinton was speaking at the launch of "Hard Hats for Hillary" in Boston.