The Heroes Act was introduced in the House of Representatives and could be voted on in the Democratically-led chamber as early as this week.
But the measure will face immediate opposition from the White House and in the Senate, as President Donald Trump and the Senate's Republican leadership have said a new round of emergency funding is not yet needed.
Congress has passed -- and Trump has signed -- multiple pandemic relief measures in recent months.
They including a massive, $2.2 trillion rescue package in March known as the Cares Act, and a subsequent $483 billion measure to pump new funds into a popular loan program for small businesses devastated by forced lockdowns.
The new bill, which House Speaker Nancy Pelosi dubs Cares 2, includes a second round of economic impact payments of up to $6,000 per household, in an effort to ease the burden for millions of Americans who have lost their jobs in the pandemic.
It also funds health care workers and emergency responders, expands virus testing and tracing, boosts lending to small businesses, bolsters housing assistance and strengthens food security for the poor.
In a statement released by Pelosi's office, House Democrats described the bill as "a bold and comprehensive coronavirus response bill that will meet the challenge this pandemic poses to our nation."
The United States, the world's hardest hit nation, has recorded more than 1.35 million confirmed infections of COVID-19, including 80,000 deaths.