The US Senate passed a $100 billion emergency package Wednesday to help Americans hit hard financially by the coronavirus crisis, with more federal assistance in the pipeline.

The bipartisan measure would provide for free coronavirus testing, sick pay and paid family leave, and bolster unemployment insurance for millions of Americans.

Senators voted 90 to eight for the bill, which earlier cleared the House of Representatives and now goes to President Donald Trump for his signature.

The legislation aims to strengthen protections in the face of a global health crisis that has already killed more than 110 people in the United States, where more than 7,300 cases have been confirmed.

Senate Majority Leader Mitch McConnell, speaking moments after the vote, called it "a very important" step.

The so-called Phase Two bill is the second emergency congressional aid package related to coronavirus, following an initial $8.3 billion measure passed early this month.

McConnell acknowledged the urgent need to get relief to workers, but stressed he would compel the chamber to stay in session until a broader, Phase Three relief package is completed.

"I will not adjourn the Senate until we have passed a far bolder package that must include significant relief for small businesses all across our country," McConnell said.

"Just how long it will take to go through these steps is unclear," he added. "We are moving rapidly because the situation demands it."

The White House and lawmakers are negotiating a $1.3 trillion package -- among the largest federal emergency plans ever -- that reportedly would include up to $500 billion in direct check payments to Americans and up to $500 billion for small businesses, as well as the full $50 billion the airline industry has requested.

Treasury Secretary Steven Mnuchin said it would also include $300 billion in deferred tax payments.

Wednesday's vote took place under extraordinary circumstances, with roll calls extended to 30 minutes to allow senators to comply with US health precautions.

"Be aware of the social distancing... as we come over to the chamber and as we depart," McConnell told colleagues, urging against congregating on the Senate floor.

The vote came after Mnuchin went to the US Capitol to appease concerns by some Senate Republicans about the ramifications that sick and family leave could have on small businesses that are already suffering economically from the crisis.

"This is literally the worst time in living memory to pile even more burdens and costs onto small businesses, which are themselves fighting to stay alive, unless we back it up with major assistance," McConnell said.

Top Senate Democrat Chuck Schumer called for immediate negotiations on the stimulus.

He said Democrats are proposing "a Marshall Plan" for health infrastructure that prioritizes public health capacity, unemployment insurance, paid sick leave and priority treatment for labor in any industry bailout.