The infrastructure drama enveloping Capitol Hill could spill onto the global climate stage.

Why it matters: Major new U.S. investments and policies could help spur other nations to take more aggressive and tangible steps to cut emissions. But failure to steer major new initiatives through Congress could hinder the White House diplomatic posture as the U.N. conference looms.

State of play: The White House is negotiating with Republicans amid all kinds of uncertainty over whether Democrats can pass legislation without GOP backing.

• President Biden has proposed major investments in electric vehicles, grid tech, mass transit, clean energy tax incentives and many other initiatives.
• The negotiations with Republicans — who object to the plan's steep price tag and expansive definition of infrastructure — come ahead of November's critical United Nations climate summit.

What they're saying: "Because of the importance of American leadership on climate, the rest of the world is definitely watching what happens on Capitol Hill," said the Environmental Defense Fund's Nathaniel Keohane.

• Keohane, who leads EDF's climate program, said major U.S. investments will bolster the country's economy and competitiveness. But they're also consequential internationally, he said.
• "The more the U.S. can demonstrate leadership — not only in the ambition of its targets but in the ambition of its implementation and the seriousness of its implementation — the more likely we are to see the rest of the world stepping into its ambition and accelerating its own climate action," he said.

Catch up fast: In April the White House set a voluntary target under the Paris Agreement of cutting U.S. emissions by 50% below 2005 levels by 2030.But that's much harder to achieve absent Capitol Hill approval of new investments and incentives.

• The Atlantic Council's Margaret Jackson said Biden's climate initiatives thus far have borne some fruit, pointing to several nations strengthening their Paris targets.
• But Jackson, who has written about the importance of congressional action, also tells Axios: "U.S. allies and partners are still somewhat skeptical in terms of how much this administration can really accomplish, and will it be lasting."

What's next: Biden is slated to speak today with Sen. Shelley Moore Capito (R-W.Va.), the lead Republican on infrastructure negotiations.

• Democrats can push their plan through budget reconciliation — the process that enables certain revenue and spending measures to pass with a simple majority Senate vote.
• Those prospects in the 50-50 Senate are far from certain. Democratic Sens. Joe Manchin and Kyrsten Sinema are cool to using reconciliation.
• Commerce Secretary Gina Raimondo told ABC News yesterday that Biden will keep seeking a bipartisan deal, but added, "If we don't get there, then we'll consider other options."