WASHINGTON (REUTERS) - US Senate Republicans on Thursday (April 22) proposed a US$568 billion (S$755 billion), five-year infrastructure package as a counteroffer to President Joe Biden's sweeping US$2.3 trillion plan, calling their measure a good-faith effort towards bipartisan negotiations.

The proposal, which falls below even the range of US$600 billion to US$800 billion that Republicans floated earlier in the week, focuses narrowly on traditional infrastructure projects and broadband access.

It drew a mixed response from Democrats, who hold narrow majorities in both chambers of Congress. Some Democrats dismissed it as inadequate to the task of repairing America's infrastructure and reliant on user fees that would penalise working people.

The Republican plan would not result in higher taxes but be fully paid for with user fees on electric vehicles and other items, unspent federal funds and possible contributions from state and local governments.

"This is the largest infrastructure investment that Republicans have come forward with," said Senator Shelley Moore Capito, who has helped lead the effort as top Republican on the Senate Environment and Public Works Committee.

"We see this as an offer that's on the table and deserves a response," the West Virginia lawmaker told a news conference.

Republicans sent the proposal to Biden on Thursday, before unveiling the package, which represents less than one-quarter of the Democratic president's plan.

Democratic Senate Majority Leader Chuck Schumer had no immediate comment on the Republican proposal, but told reporters: "Any infrastructure proposal has to be green and cannot be paid for on the backs of working people."

Biden, who asked Republicans this week to offer a counterproposal by mid-May, proposed an infrastructure plan that includes not only traditional infrastructure projects but seeks to alter the course of the US economy by addressing climate change and expanding human services such as care of the elderly.

Republicans have opposed the size and scope of the Biden proposal, as well as its plan to pay for spending by raising taxes on US corporations.

Two-track approach

Thursday's proposal could form the basis of a two-track infrastructure process that would include a smaller bipartisan Bill and a larger measure that Democrats could move through Congress without Republican votes.

"It's a starting point," said Senator Joe Manchin, who has insisted that Democrats work with Republicans on infrastructure.

"I'm sure that we can find a compromise."

Manchin, a moderate Democrat from heavily Republican West Virginia, is a critical swing vote in the evenly divided Senate.

Biden has proposed US$650 billion for roads, rail and transport, but that portion of his plan also includes a US$174 billion investment in electric vehicles that is absent from the Republican framework.

Republicans would spend US$299 billion on roads and bridges, US$65 billion on broadband, US$61 billion on public transit systems, US$44 billion in airports, US$35 billion on drinking water and wastewater systems, US$20 billion on rail, US$17 billion on ports and inland waterways, US$14 billion on water storage and US$13 billion on transportation and pipeline safety.

Republican Senator Pat Toomey said state and local governments that are flush with tax revenues and Covid-19 relief funding could also be asked to help pay for infrastructure projects.

Biden and his Democratic allies in Congress could need Republican support to get infrastructure through the Senate and House of Representatives.

The Republicans' proposal echoes a narrow US$618 billion Covid-19 relief plan they put forward earlier this year in negotiations on Biden's US$1.9 trillion American Rescue Plan.

Democrats rejected the offer and instead passed the Biden package without Republican votes.