WASHINGTON (AP) — A bipartisan group of senators reached a tentative framework on an infrastructure deal Wednesday ahead of a crucial meeting with President Joe Biden at the White House.

That's according to a person familiar with the negotiations who spoke on condition of anonymity to discuss the private talks. Biden has invited members from the group of 21 senators to the White House on Thursday.

“The group made progress towards an outline of a potential agreement, and the President has invited the group to come to the White House tomorrow to discuss this in person,” White House press secretary Jen Psaki said late Wednesday.

Biden's top aides met with senators for back-to-back meetings on Capitol Hill and later huddled with House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer as the president reaches for a signature domestic achievement with his sweeping $4 trillion infrastructure plans.

The group had been narrowing on a much smaller but still sizable $1 trillion proposal of road, highway and other traditional infrastructure projects. They have struggled over how to pay for an estimated $579 billion in new spending.

“I would say that we’re very, very close, and we’re going to now do the outreach," Republican Sen. Rob Portman of Ohio told reporters on Capitol Hill as he left an evening meeting with the other senators and White House team.

“We have a good, good, balanced group of pay-fors. That was important to both sides, I will say, in good faith we tried to get there. We didn’t agree on everything, but we were able to get there," he said.

With Republicans opposed to Biden's proposed corporate tax rate increase, from 21% to 28%, the group has looked at other ways to raise revenue. Biden rejected their idea to allow gas taxes paid at the pump to rise with inflation, viewing it as a financial burden on American drivers.

Biden has sought $1.7 trillion in his American Jobs Plan, part of nearly $4 trillion in broad infrastructure spending on roads, bridges and broadband internet but also the so-called care economy of child care centers, hospitals and elder care.

Psaki said the senior staff to the president had two productive meetings with the bipartisan group at the Capitol. The White House team was huddled late into the evening with the Democratic leaders.

“We got our framework. We’re going to the White House," Sen. Mark Warner, D-Va., told reporters. “We wouldn’t be going to the White House if we didn’t think it has broad-based support.”