President Joe Biden is scheduled to speak to reporters from the White House Thursday afternoon to discuss a breakthrough infrastructure deal to fix the nation’s highways, bridges and waterways.

The address came just hours after Biden declared that the White House had reached a deal with a bipartisan group of senators over infrastructure, though key details over how to pay for the massive undertaking remain uncertain.

The framework will include $579 billion in new spending, the White House said. Some $312 billion will go to transportation, with $109 billion invested in roads, bridges and other major projects, $66 billion in passenger and freight rail and $49 billion in public transit.