"No matter what EV you drive, we want to make sure that you will be able to plug in, know the price you're going to be paying, and charge up in a predictable, user-friendly experience," Transportation Secretary Pete Buttigieg told reporters in a preview of the rules. The first tranche of the billions in federal funds will now be rolled out to states in upcoming weeks, forcing companies like Tesla, EVgo Inc, and ChargePoint Holdings Inc. to jockey for their share of the funds from state governments.

The network is a central part of U.S. President Joe Biden's plan to tackle climate change by converting 50 percent of all new U.S. vehicle sales to electric by 2030. A shortage of chargers on U.S. roads has slowed the growth of EV sales and the positive environmental impact, advocates say.

Manufacturers warned before the rules were released that imposing a domestic components quota too soon in the program rule would slow the rollout. White House National Climate Adviser Ali Zaidi said that under Biden's leadership the number of EV models being offered to consumers has doubled, along with the number of charging stations and EV sales.

"So this is not pie in the sky. It's literally steel in the ground. We are seeing the Biden climate vision on wheels," Zaidi said.

Under the 2021 bipartisan infrastructure law, federal infrastructure projects like EV chargers must obtain at least 55 percent of construction materials, including iron and steel, from domestic sources and have all manufacturing done in the United States starting immediately. However, the Department of Transportation requested a waiver for EV charging stations and initially proposed that at least 25 percent of the chargers' overall cost come from American-made components starting in July of this year and then 55 percent by Jan. 1, 2024.

The new rules ditch the two-step process and start imposing the component cost provision in July 2024 at 55 percent. The chargers must be assembled at a U.S. factory, and any iron or steel charger enclosures or housing must be made in the U.S., starting immediately. The U.S. and its allies Mexico and the European Union have clashed over protectionist policies implemented by Biden. The U.S. and the EU set up a task force last year to look at American laws that Europeans fear will discriminate against foreign electric car makers.

EV chargers require iron and steel for some of their most crucial parts, including the internal structural frame, heating and cooling fans and the power transformer. Chargers with cabinets that house the product require even more steel, making up to 50 percent of the total cost of the chargers in some cases.

Global demand for EV chargers is putting strain on the supply chain that makes it difficult, if not impossible, to meet the made-in-America standards and expedite construction of new chargers, states and companies warned in comments to the Department of Transportation.

Tesla told the DOT that the plan was "aggressive" and "could lead to a shortfall in the number of compliant charging stations available given the pace and scale of deployment," records show. However, labor advocates argue that delaying or skirting the requirements undercuts congressional intent and punishes companies that moved early to comply with the rules.