Both New York State and New Jersey stand ready to commit state funds to build a new Hudson River rail tunnel — as long as the federal government picks up half the tab.

Governors Andrew Cuomo and Chris Christie publicly released a letter addressed to President Barack Obama asking Washington D.C. to help pay for the $20 billion project.

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If it comes to fruition, the new track would boost Amtrak service currently reliant on a 150-year-old, Superstorm Sandy-damaged rail line.

"[The] project is simply impossible without federal assistance," Cuomo and Christie wrote. 

Telling the White House that their "shovels are ready," the governors also committed their respective states' resources as well as the Port Authority of New York and New Jersey's to develop a funding plan so as to secure federal help.

"The congressional delegations of New York and New Jersey are united in a manner we have rarely seen before," they added.

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News of the tunnel comes five years after Christie pulled the plug on an earlier Hudson tunnel project between the states — Access to the Region's Core, or ARC.

U.S. Department of Transportation Secretary Anthony Foxx said in a statement that D.C. would work towards "an equitable split between the states and the federal government using our existing grant and financing programs and whatever new resources can be provided by Congress."

The existing tunnel is part of the Northeast Corridor route, which some 750,000 commuters rely on daily.

About 90,000 people commute between states on either Amtrak or NJ Transit every day.