New York Gov. Andrew M. Cuomo and New Jersey Gov. Chris Christie are calling for an independent review of Penn Station’s infrastructure, and how Amtrak maintains it, following two train derailments there that caused massive delays for commuters in recent weeks.

In a letter Monday to Amtrak’s CEO Charles “Wick” Moorman and Federal Railroad Administration Executive Director Patrick Warren, Cuomo and Christie said the train derailments and severe service disruptions at the century-old Manhattan rail hub have made clear “the need for a complete review of Amtrak’s infrastructure and maintenance protocols.”

Amtrak last week said it had already launched a comprehensive joint inspection of Penn’s infrastructure with the FRA, which oversees U.S. railway safety, and would also review its own maintenance protocols. But in their letter, Cuomo and Christie said that those announced efforts don’t go far enough, and that Amtrak has not reached out to New York or New Jersey to be involved.

“As the primary users of Penn Station via the Long Island Rail Road and NJ Transit, New York and New Jersey are requesting independent verification of track safety at Penn Station,” the governors wrote. “Specifically, this comprehensive review should take into account the causes of recent failures at Penn Station and any needed changes to the processes by which routine maintenance and emergency repairs are performed.”

In a statement Monday, Amtrak said it is “committed to improving the immediate conditions at Penn Station while working with all our partners to address the lack of capacity and aging assets that threaten the reliable operation” at Penn. Amtrak did not say whether it would include other railroads in its review but will “immediately share these findings with NJ Transit and the Long Island Rail Road and work with them to develop an expedited plan to ensure that our passengers have safe and efficient service.”

The FRA did not respond to requests for comment Monday.

The letter contained Cuomo’s first public comments on Amtrak since an NJ Transit train derailed a week ago as it pulled into Penn, the nation’s busiest rail hub, because of weakened wooden rail ties at the station, owned and maintained by Amtrak. As a result, the LIRR gave up four tracks it typically has to itself so NJ Transit and Amtrak could continue operating at Penn.

Just 10 days earlier, an Amtrak Acela train derailed after it rode over “mismatched” pieces of rail. The two derailments, and various other infrastructure-related failures in and around Penn in recent weeks, triggered major LIRR service disruptions, including delays and cancellations.

The railroad runs about half of all the trains that travel into and out of the busy transit hub, carrying 230,000 riders daily. NJ Transit transports an additional 200,000 customers a day through Penn Station. Amtrak’s Acela and other trains provide critical service among East Coast cities.

“These riders, residents of our states, deserve safe and reliable rail service,” Cuomo and Christie wrote. “Severe service disruptions at Penn Station not only impact and inconvenience riders, but also create a ripple effect across the region. Our passengers and our residents deserve better.”

A New York State official said Monday that the letter was prompted in part by the Cuomo administration’s “frustration on behalf of Long Island commuters who are grossly underserved.”

Last week, in a letter to Amtrak Chairman Anthony Coscia, Christie said he would direct NJ Transit to withhold funding from Amtrak because the recent incidents in Penn Station indicate the agency “does not take its obligations seriously.”

NJ Transit Executive Director Steven Santoro also chided Amtrak’s maintenance practices last week, calling for his agency, the LIRR and Amtrak to join in a comprehensive analysis of tracks and signals at Penn.

The Metropolitan Transportation Authority’s two top leaders, interim executive director Veronique Hakim and acting agency chairman Fernando Ferrer, also wrote to Amtrak last week, blasting the agency for a series of “unacceptable infrastructure failures” at Penn and requesting to re-examine the decades-old agreement under which the different railroads share space at the station.

An MTA spokeswoman declined to comment further Monday.