The United States secretary of transportation wants Gov. Chris Christie and New York Gov. Andrew Cuomo to get serious about new Hudson River train tunnels.

In a letter obtained by News 12 New Jersey, Secretary Anthony Foxx asks the governors for their support of Amtrak's Gateway tunnel project.

In the letter, Secretary Foxx calls the conditions of the Hudson River tunnels "a major threat to the region and our nation's transportation system."

Foxx says the Obama administration was willing to put billions of dollars behind the ARC tunnel project five years ago, but since Gov. Christie pulled New Jersey out of that deal, nothing has happened to improve rail access. Christie cited cost concerns as his reason for not going ahead with the project.

Damage caused by Superstorm Sandy has only made the tunnels less stable. Foxx says, "It is increasingly clear that the problems of this crumbling asset will not go away."

Foxx committed to putting some money behind the project, but says that it will take more than federal money. He says that the Federal Railroad Administration and Amtrak have been in discussions about possible federal financing that could get the project started.

"Neither Amtrak nor [New York or New Jersey], acting alone, can replace these tunnels. It will take all of us working together," Foxx says in the letter.

The secretary also says he wants to meet with the two governors within the next two weeks.