President Joe Biden said Monday he hopes Democrats will strike a deal on two massive spending packages this week and make America the "most advanced country in the world" again.

Speaking at the start of a crucial period for his presidency and the Democratic Party's wider fortunes, Biden urged a deal on a social spending bill expected to weigh in at a little less than $2 trillion and an infrastructure bill worth $1.2 trillion.

He said he wanted a deal by the end of this week, when he flies to two summits in Europe.

"That's my hope," he told reporters, adding that talks on Sunday with one of the main obstacles to agreement, moderate Democratic Senator Joe Manchin, "went well."

US President Joe Biden heads to New Jersey at the start of a crucial week for his spending plans and the Democratic party US President Joe Biden heads to New Jersey at the start of a crucial week for his spending plans and the Democratic party Photo: AFP / Brendan Smialowski

Later, in a speech at a train maintenance depot in New Jersey, Biden said the United States had fallen behind other major countries in infrastructure, education and other basic services.

"What are we doing?" he said. "Let's get to work, let's put people to work, let's once again reestablish America is the most advanced country in the world."

Democrats narrowly control Congress but have been feuding for weeks over the contents and scope of the social spending bill, with moderates forcing down the original $3.5 trillion price tag and left-leaning members retaliating by threatening to sink the otherwise popular infrastructure package.

The mess has left Biden scrambling to rescue his dream of emulating the great big-government presidents, like Franklin Roosevelt, and puts Democrats at ever-growing risk of losing Congress in next year's midterm elections.

US president Joe Biden visits an elementary school in New Jersey US president Joe Biden visits an elementary school in New Jersey Photo: AFP / ANDREW CABALLERO-REYNOLDS

The 78-year-old president hopes for a win now to buoy his credibility as he goes to the G20 summit in Rome on the weekend, followed by next week's UN climate summit in Glasgow.

Another deadline of sorts is November 2, when the Democratic candidates for governor of New Jersey and especially Virginia face difficult reelections.

Popular former president Barack Obama has already campaigned in both states and Biden is set to follow Monday's New Jersey trip with a visit to Virginia on Tuesday.

However, analysts say that if congressional Democrats fail to produce the long-delayed spending bills by then, Biden's endorsement and Democratic enthusiasm in general could fall flat, giving Republican opponents a momentum-changing victory.

US president Joe Biden wants a deal from his Democrats by the end of the week on infrastructure and social spending US president Joe Biden wants a deal from his Democrats by the end of the week on infrastructure and social spending Photo: AFP / ANDREW CABALLERO-REYNOLDS

In New Jersey, Governor Phil Murphy has seen his 26-point lead over the Republican challenger drop to six points.

The alarm bells are even louder in Virginia, a state Biden won easily in his election a year ago against Trump.

Now, the Democratic candidate for governor, Terry McAuliffe, is in a dead heat with Republican Glenn Youngkin and Biden's own popularity ratings are tanking.

Democratic Party leaders have been ramping up predictions of success for a week.

Manchin told reporters Monday in Washington that there "should" be a framework agreement on the social spending by the end of the week, although not an actual vote.

On Sunday, House Speaker Nancy Pelosi said "we're almost there."

Some of the most complex negotiations have been over how to pay for the spending, with Biden reluctantly conceding he will need to abandon his push for higher corporate taxes. A novel tax on ultra-wealthy individuals is being discussed.

At the same time, slashing the wish list to around half of the original $3.5 trillion has triggered fierce turf battles over programs and whether to cut items out entirely or simply to provide less funding.

Among the big items that Biden has agreed to lose is his passionate drive for free community college -- an idea given impetus by his wife, Jill, who teaches English at a community college in Virginia.

However, universal pre-kindergarten and childcare subsidies are expected to survive, as well as more money for state-backed healthcare. Up in the air still is the fate of proposals for spending on climate change mitigation.