President Biden holds a mask after speaking Tuesday at the White House about efforts to combat COVID-19. Vice President Kamala Harris is at left. Associated Press/Evan Vucci

WASHINGTON — President Joe Biden urged Senate Democrats on Tuesday to rally behind a $1.9 trillion COVID-relief bill and stood by his proposed $1,400 payments to individuals, even as some party moderates sought to dial back parts of the package.

“He said we need to pass this bill and pass it soon. That’s what the American people sent us here to do, and we have to get America the help it needs,” Senate Majority Leader Chuck Schumer, D-N.Y., told reporters, describing a 20-minute conference call Biden had with Democratic senators.

The president’s cry for unity came as Democrats, with no votes to spare in a 50-50 Senate, sorted through lingering divisions over the emerging bill. Those included moderates’ efforts to focus spending more narrowly on those hardest hit by the deadly pandemic and resulting economic contraction.

Biden took to Twitter to signal he wouldn’t budge from his demand that lawmakers add a fresh $1,400 payment to the $600 that millions of individuals received from a December relief measure. That new installment comprises nearly a quarter of the overall bill’s cost.

“The fact is that $600 is not enough. The Senate needs to pass the American Rescue Plan and finish the job of delivering $2,000 in direct relief,” Biden wrote in one of his infrequent uses of a medium his predecessor, Donald Trump, at times used over 100 times daily.

The huge relief package is a too-big-to-fail moment for the fledging president, who would be politically staggered if Congress — controlled narrowly by Democrats but controlled nonetheless — failed to deliver. Conquering the virus that’s killed half a million Americans and flung the economy and countless lives into tailspins is Biden’s top initial priority.

So far, Republicans are following the template they set during Barack Obama’s presidency. Senate Minority Leader Mitch McConnell, R-Ky., said he hoped GOP senators would oppose the bill unanimously, as their House counterparts did early Saturday when that chamber approved its version of the measure.

McConnell accused Democrats of ignoring signs that the economy and the deadly virus’ rampage were beginning to turn around and shunning Republicans. Biden met with 10 GOP senators last month who presented a $600 billion plan one-third the size of his own, but efforts to find middle ground went nowhere.

“The new administration made a conscious effort to jam us,” McConnell told reporters. “We’ll be fighting this in every way that we can.”

Democrats are using special rules that will let them avoid Republican filibusters that would require them to garner an impossible 60 votes to approve the legislation.

The Senate bill was expected to largely mirror the House-approved package, with the most glaring divergence the Senate’s dropping of language boosting the federal minimum wage to $15 hourly.

Schumer said Senate debate would commence as soon as Wednesday and predicted, “We’ll have the votes we need to pass the bill.” Democrats want to send a final package to Biden by March 14, when an earlier round of emergency jobless benefits expires.

The bill has hundreds of billions of dollars for schools and colleges, COVID-19 vaccines and testing, mass transit systems, renters and small businesses. It also has money for child care, tax breaks for families with children and assistance for states willing to expand Medicaid coverage for low-income residents.

Two people said Biden told Democrats they must sometimes accept provisions in a large measure that they don’t like. And it was clear there were still moving parts.

West Virginia Sen. Joe Manchin, perhaps the Senate’s most conservative Democrat, said he wanted to pare the bill’s $400 weekly emergency unemployment benefit to $300. That’s the same amount Congress approved last December — on top of regular state benefits — and Manchin said the higher figure would discourage people from returning to work.

“It would be awful for the doors to open up and there’s no one working,” Manchin said of businesses reopening. Top Democrats and progressives oppose trimming those benefits, but Schumer suggested a final decision awaited, saying, “They’re discussing it.”

Independent Sen. Angus King of Maine said he wants the bill’s $350 billion for state and local governments to specify minimum amounts for municipal governments and has called for $50 billion to improve broadband coverage.

Despite every Democrats’ huge leverage because all their votes are needed, none have so far threatened to sink the legislation if they don’t get their way. All are aware of how that would rattle Biden’s presidency and Democrats’ ability to be productive during this Congress.

“We want to get the biggest, strongest bill that can pass, and that’s what we’re going to do,” Schumer said.

There were indications loose ends were falling into place. In one sign, 11 Democratic senators wrote Biden urging him to use a huge, upcoming infrastructure bill to create regularly paid relief and jobless benefits that would be automatically triggered by economic conditions.

Some progressives had wanted those payments included in the COVID-19 bill. Democrats’ push to include it in later legislation suggested an effort to satisfy progressives while avoiding jeopardizing the current package.

Progressives, though, were still smarting over the virtual certainty that the Senate bill will lack the minimum wage boost, up from $7.25 hourly locked in since 2009.

The chamber’s nonpartisan parliamentarian said last week that including that increase violated Senate budget rules. Opposition by moderates including Manchin and Sen. Kyrsten Sinema, D-Ariz., has left Democrats without the votes needed to salvage it.

A fundraising email by Our Revolution, a progressive political committee that was started by backers of Sen. Bernie Sanders, I-Vt., underscored the left’s anger. Sanders is chief Senate sponsor of the wage increase.

“The politician standing in the way of change is Vice President Kamala Harris,” said the email, citing the possibility — already rejected by the White House — of her casting a tie-breaking Senate vote to overrule the parliamentarian. It said the organization will “hold her accountable if she decides to turn her back on essential workers.”

Senate drafters of the legislation also stripped out a small provision that would have provided $1.5 million for maintaining and operating a bridge in upstate New York connecting the U.S. and Canada. The funding was removed after some Republican lawmakers had criticized it as an example of a wasteful spending item that should not be part of the COVID relief bill.