Defining "infrastructure" is a major challenge in negotiations for a bipartisan infrastructure deal, in addition to the debate over how to pay for it.

Republicans unveiled their $928 billion infrastructure counterproposal on May 27, largely focused on traditional infrastructure, but Democrats are pushing back, saying climate change measures must be included in any agreement.

Senate Republicans argue the package should be focused on physical infrastructure like roads, highways and bridges — areas where both sides agree work needs to be done. The White House responded to the GOP proposal saying the overall spending increase is encouraging, but the plan still doesn't include enough to fix veterans' hospitals, remove lead pipes and transition to clean energy.

"It's moving in the right direction, but we cannot continue to add social programs. We have got to add true infrastructure," said Sen. Tommy Tuberville (R., Ala.) in an interview with Yahoo Finance. "If we get true infrastructure we'll jump all over it, because we've kicked the can down the road for so long."

Democrats argue investments in clean energy do represent infrastructure. Sen. Ron Wyden (D., Ore.) bashed the Republican plan in a statement, saying clean energy investments will create jobs while helping the U.S. meet its climate goals.

"A so-called infrastructure proposal that does nothing to move toward a clean-energy future is not a serious proposal," said Wyden. "It’s been 12 years since Democrats last had a real opportunity to pass climate legislation. And if Republicans aren’t serious, we can’t afford to wait another 12 years. We need to keep moving forward.”

"I think those proposals in the future, they might have some meat to them, so to speak, but for us right now to get our economy back after this pandemic, to get commerce going, to get people back to work, we have got to do real infrastructure," said Tuberville. "We have got to get back the basics of this country and that's having true infrastructure and getting it back to where our commerce can really thrive."

The White House says it will continue to work with lawmakers throughout the week. If negotiations fail, Democrats could try and pass President Biden's infrastructure plan through the reconciliation process without any Republican support.

Some Democrats argue including measures to fight climate change is non-negotiable — and the administration will likely face increased pressure from progressives to move ahead with or without Republicans in the days ahead.

Republicans warn against pushing partisan legislation through, saying it will hurt the chances of bipartisan cooperation in the future — though they used the same process to pass tax cuts without Democratic support in 2017.

"Let's involve bipartisanship, have true infrastructure, do it the right way," said Tuberville. "Have everybody on board and let the American people know that we're up here working for them and not working against each other."

Jessica Smith is chief political correspondent for Yahoo Finance, based in Washington, D.C. Follow her on Twitter at @JessicaASmith8.

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