WASHINGTON, March 16 (Reuters) - A group of 20 state attorneys general said on Monday the Trump administration proposal to boost American parts and components in federally funded electric vehicle charging stations would effectively make the $5 billion program unusable.

The attorneys general from states including California, Colorado, Arizona, New York, Virginia, Illinois and Michigan, said the U.S. Transportation Department proposal to hike so-called "Buy America" requirements from 55% to 100% would make it "impossible for manufacturers to achieve, frustrate congressional intent, and impair the public interest by slowing or halting federally funded EV charger deployment nationwide." 

USDOT and the White House did not immediately respond to a request for comment.

In January, U.S. District Judge Tana Lin ruled the Trump administration unlawfully suspended funding awarded to support the expansion of electric vehicle charger infrastructure, in a victory for 20 Democratic-led states that sued over the action.

The Democratic state attorneys general - joined by Kentucky Governor Andy Beshear - suggested the USDOT proposal on EV charger content "is yet another effort to carry out the president's directive to halt congressionally mandated funding for EV infrastructure."

The states support requiring Buy America rules but said the USDOT proposal is not feasible.

"There are currently no 100% domestically produced chargers available for purchase, there is not enough demand for 100% domestically produced chargers to justify investing in domestic production, and some critical components of the chargers are simply not produced in the United States," they said in the letter.

The states sued USDOT after it suspended the $5 billion National Electric Vehicle Infrastructure Formula Program, which was part of a 2021 infrastructure law enacted by Congress in 2021 under Democratic President Joe Biden.

The proposal would take immediate effect once the changes are finalized. The Sierra Club called the proposal another bad-faith attempt to kill the program by the Trump administration and would prevent funds from being used.

The Trump administration has pursued numerous policies to boost the sale of gas-powered vehicles and cut EV incentives for automakers and consumers.

A funding bill approved in January by Congress redirected $879 million in funds approved under Biden for the EV charging network to other infrastructure priorities.