The U.S. Supreme Court on Thursday temporarily blocked the state of New Jersey from withdrawing from a bistate commission formed in the 1950s to investigate corruption at the New York region’s ports.

The court's order sided with the state of New York, which had petitioned the Supreme Court this month to block New Jersey from leaving the Waterfront Commission of New York Harbor. It had said it would do so by March 28.

New Jersey Democratic Gov. Phil Murphy said in a statement Thursday he was disappointed by the high court’s decision but he’s optimistic that the state will eventually be “vindicated” and able to withdraw from the commission.

“I will not give up the fight to protect New Jersey’s interests, which are poorly served by a commission that operates without transparency and has long outlived its usefulness,” Murphy said.

In court filings, New York has claimed New Jersey can’t unilaterally withdraw from the commission under the terms of the compact signed by the two states in 1953, during an era of rampant corruption in the unions representing dock workers. It noted recent criminal prosecutions of reputed mob associates to assert that organized crime still has some influence at the ports.

In a statement Thursday, Democratic New York Gov. Kathy Hochul called the decision “a victory for the safety of New Yorkers and for the health of our economy.”

New Jersey has contended that organized crime has largely been driven out of the ports and that the commission impedes job growth by overregulating businesses there and making hiring more difficult. It also notes that 90% of activity at the ports is on the New Jersey side, in Newark, Elizabeth and Bayonne, as opposed to decades past when most was centered in New York.

The New York-New Jersey port system is the busiest on the East Coast and ranks third in the U.S. behind Los Angeles and Long Beach, California.

The commission itself was forced to clean house in the wake of a 2009 report by New York's inspector general that detailed improper hiring and licensing practices, misappropriation of forfeiture funds and misuse of Homeland Security grants. In one case, the IG reported, senior officials looked the other way as a convicted felon was allowed to continue operating a warehouse by putting it in his wife's name, in violation of commission rules.

Under a law signed by Republican Gov. Chris Christie withdrawing New Jersey from the commission in 2018, New Jersey state police would take over policing the ports, including performing background checks for prospective hires.

A federal judge blocked the state’s attempt in 2019, but an appeals court reversed last year and wrote that New Jersey was protected from the commission’s challenge by sovereign immunity.

Through its attorney, the Waterfront Commission declined comment Thursday.