By David Shepardson

(Reuters) – The Trump administration may withhold environmental approvals for Manhattan transportation projects if New York state does not end congestion pricing, U.S. Transportation Secretary Sean Duffy said on Monday.

Duffy told New York Governor Kathy Hochul she must respond by May 21 and said the department could start taking actions on May 28. Hochul ignored an April 20 deadline set by Duffy to end the program, which since its commencement in January charges most passenger vehicles a $9 toll during peak periods to enter Manhattan south of 60th Street.

“The federal government sends billions to New York — but we won’t foot the bill if Governor Hochul continues to implement an illegal toll to backfill the budget of New York’s failing transit system,” Duffy said. “We are giving New York one last chance to turn back or prove their actions are not illegal.”

Hochul, in a statement released by her office, said: “I received the letter from USDOT extending their congestion pricing threats once again. I repeat: congestion pricing is legal — and it’s working. Traffic is down, business is up and the cameras are staying on.”

The Transportation Department, under the administration of Democratic President Joe Biden, had approved the congestion program in November, which is monitored via electronic license plate readers. U.S. approval is needed because it involves tolls on federal highways.

The program is administered by New York’s Metropolitan Transit Authority, the state agency that also oversees New York City’s subway system.

The program, which follows similar programs in other cities including London and Singapore, aims to raise revenue to fund mass transit capital improvements. Officials say it has cut down traffic and sped up the flow of vehicles.

Opponents, including Duffy, say the scheme takes money from working people and leaves drivers without a free highway option.

The Transportation Department could stop issuing advance construction authorizations or environmental approvals in Manhattan except for safety projects beginning in late May. Duffy also warned that if the state continued to refuse to comply, the Transportation Department could stop awarding funds for non-safety-related projects within New York City and could expand sanctions to other areas in New York state.

Duffy in March had extended the deadline after he had rescinded federal approval in February.

Duffy separately threatened to withhold federal transit funds from the MTA over crime and safety on the New York City subway system. The MTA in response had said it had sharply reduced crime.