WASHINGTON (Reuters) - The U.S. Congress on Monday inched toward a $450 billion deal to help small businesses and hospitals hurt by the coronavirus pandemic, with House Speaker Nancy Pelosi saying negotiators had come to terms on the ‘principles’ of the package as the Senate set a Tuesday session for a potential vote.

Republicans and Democrats have been battling for more than a week over what to include in the fourth round of financial stimulus intended to ease the heavy economic toll of a pandemic that has killed more than 42,000 Americans.

In an interview with CNN, Pelosi said Republican and Democratic negotiators were still in talks, adding: “I feel very optimistic and hopeful that we’ll come to a conclusion tonight.”

“We have I believe come to terms on the principles of the legislation, which is a good thing ... now we’re down to the fine print,” Pelosi said.

The two sides had sought to finish the package earlier on Monday, but failed amid continued disagreements over, among other things, a coronavirus testing strategy.

“However, since this is so urgent, I’ve asked that the Senate meet again ... and the Democratic leader has agreed to my request,” Majority Leader Mitch McConnell said on the Senate floor.

The 78-year-old Republican then left the chamber, putting on a mask to speak briefly with reporters in the hallway.

Pelosi had told fellow congressional Democrats on a conference call she believed an agreement could be reached on Monday night, and Majority Leader Steny Hoyer said a vote was possible on the House of Representatives floor on Wednesday, according to a Democratic aide familiar with the call.

President Donald Trump told a White House news briefing he hoped congressional negotiators would reach a deal soon.

“A lot of progress has been made on that,” he said.

A deal would end a stalemate over Trump’s request to add to a small-business loan program. Congress set up the program last month as part of a $2.3 trillion coronavirus economic relief plan, but it has already run out of money.

McConnell complained that an agreement had not been reached because “our Democratic colleagues are still prolonging their discussions with the (Trump) administration.”

‘NATIONAL STRATEGY FOR TESTING’

FILE PHOTO: Senate Majority Leader Mitch McConnell (R-KY) walks to the Senate floor during a Senate Pro Forma session on Capitol Hill, while the spread of the coronavirus disease (COVID-19) continues in Washington, U.S., April 16, 2020. REUTERS/Tom Brenner

Pelosi told CNN there would be about $120 billion in the small-business aid package geared to underbanked, minority-owned businesses. She said Democrats also were seeking $75 billion for hospitals and $25 billion for testing.

“Testing is one of the places where we want the language to be as good as we can agree to; that we need a national strategy for testing,” Pelosi said.

Widespread testing is crucial before U.S. governors can lift extensive stay-at-home orders and advisories intended to slow the spread of the respiratory disease. Trump has talked about testing as largely a state responsibility.

Representative Lee Zeldin, a Republican, said on Fox News that a bipartisan deal that would include $310 billion for small-business aid was progressing.

Zeldin said at least $50 billion more would be available for a separate small-business loan program under the deal, a provision still under negotiation. A Democratic source familiar with the talks has said that figure was more likely to be $60 billion.

But Republican Senator Bill Cassidy said aid for states and municipalities sought by Democrats would be excluded in the current plan. Trump said on Sunday he favored more aid for state and local governments but that it could be provided later.

That apparent omission was one reason a leading progressive Democrat, Representative Alexandria Ocasio-Cortez, denounced the outlines of the bill, calling it “insulting.”

If the Republican-majority Senate passes the bill on Tuesday, it could move to the Democratic-majority House as soon as Wednesday. Leaders there have told members they may try using a remote proxy voting system that a leading Democrat has proposed, said Representative Mark Pocan.

The proxy system would mean not all of the House’s 429 current members would have to be present for the vote, reducing the threat of spreading the coronavirus.