The underground museum commemorating victims of the 9/11 attacks was scheduled to open in September on the 11th anniversary of the disaster, a year after the opening of a memorial at the site that has already drawn 1 million visitors.
But in recent months, the National September 11 Memorial & Museum foundation has been fighting with the Port Authority of New York and New Jersey over who is responsible for paying millions of dollars in infrastructure costs related to the project.
The Port Authority, which owned the trade center and is building the museum, claims that the foundation owes it $300 million. The foundation claims that the authority actually owes it $140 million, because of delays in the project.
The dispute has been simmering for some time, and some details of the work slowdown were reported in November, but Thursday marked the first time that the mayor and other officials have acknowledged that the fight would mean the museum will not open in 2012.
"There is no chance of it being open on time. Work has basically stopped," Bloomberg said. New York Gov. Andrew Cuomo said on a recent radio program that the Port Authority was "on the verge" of suing the foundation, but both the mayor and the Port Authority said Thursday that negotiations over the matter continue.
"I'm sure we are going to work something out with the Port Authority," Bloomberg said. "They've got a difficult budget situation. I'm sympathetic to that."
Despite security hurdles and ongoing construction, tourists from around the world have already made the memorial at the site a regular stop on their visits to New York City. Since it opened to the public Sept. 12, more than 1 million people have visited the memorial plaza, officials said.
The site now draws about 10,000 visitors a day, which would put it on pace to match or exceed the 3.5 million who visit the Statue of Liberty and Empire State Building annually.
Tourists - some reverent, some just there to gawk - have long been a staple at ground zero, but until this summer the closest they could get were the high fences that ringed a bustling construction zone where the twin towers once stood.
Negotiating fences and legions of construction workers is still part of any trip to the memorial. All visitors must reserve free tickets in advance and pass through a security screening. But the hurdles haven't stopped people from coming. Memorial officials said visitors have hailed from all 50 states and 120 countries.
Anthoula Katsimatides, a memorial board member whose brother, John, was killed at the trade center, said the attention is welcome.
"It truly touches my heart and reaffirms the importance of this memorial to know a million people have already come here to honor and pay respects to my brother and the thousands of other loved ones who died in the attacks," she said in a written statement.
Visitors to the site today can walk on a tree-covered plaza and see the two massive pools that sit in the footprints of the fallen towers. Each pool is ringed by waterfalls, and a parapet engraved with the names of the nearly 3,000 people who died on 9/11 and in a 1993 bomb attack.
Visitors can also get a close-up look on construction of One World Trade Center, now 90 stories high and on its way to being the nation's tallest building.
Associated Press writer Samantha Gross contributed to this report.
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