President Donald Trump dropped his own New Year's ball—in the form of a wrecking ball—with a late Friday afternoon announcement that effectively wipes out plans for perhaps the nation's most crucial infrastructure project.

The president officially scrapped his predecessor's proposal to have the federal government underwrite half the cost of a multi-billion-dollar Amtrak tunnel connecting New Jersey to Penn Station, the busiest transit hub in the U.S. The lone existing tunnel is rapidly deteriorating, threatening to sever Amtrak's popular Northeast Corridor and to divert tens of thousands of New Jerseyans from their daily Manhattan commutes via New Jersey Transit.

The administration released the news on the cusp of a holiday weekend in a letter from a top Federal Transit Administration official to Gov. Andrew Cuomo and his New Jersey counterpart Chris Christie, who had agreed with the Obama administration to split the project's costs 50-50.

President Barack Obama's Department of Transportation, which encompasses the FTA, had consented to that framework with Christie, Cuomo, now-Senate Minority Leader Charles Schumer and New Jersey Sen. Corey Booker in 2015.

Friday's letter, in response to an updated proposal by the two states to fund their half of the plan with federal loans, declared the deal null and void.

"Your letter also references a non-existent '50/50' agreement between USDOT, New York, and New Jersey. There is no such agreement," wrote FTA Deputy Administrator K. Jane Williams. "We consider it unhelpful to reference a non-existent 'agreement' rather than directly address the responsibility for funding a local project where nine out of 10 passengers are local transit riders."