NEW YORK – Police and the World Trade Center site's owner sketched out a security agreement Thursday that settles a turf war over who will protect ground zero against terrorism as the Lower Manhattan site is rebuilt.

The New York Police Department and the Port Authority of New York and New Jersey agreed to devise a strategy to police streets, private office towers and public facilities, including a Sept. 11 memorial.

Police and Port Authority officials were still working out the details. “The next step will be to work closely with NYPD to develop a comprehensive security plan for the site,” said Chris Ward, executive director of the Port Authority, which owns the site.

Under the agreement, a special NYPD unit of 600 officers will patrol the site, manage security operations and oversee screening and vehicle access. The Port Authority will have primary responsibility for security at the PATH train station and will oversee the installation and maintenance of all security equipment at the World Trade Center.

City officials said the agreement would accelerate the rebuilding effort. Plans for five office towers, the memorial, a transit hub and a performing arts center were announced five years ago, but all of the projects are behind schedule.

Mayor Michael Bloomberg said the pact would ensure “seamless security that will keep the World Trade Center site safe and accessible.”

Before Sept. 11, security at the World Trade Center was largely the Port Authority's responsibility. The NYPD recently proposed taking charge of security there, and police have wielded some power over its redevelopment.

“Considering the history of this site and the ongoing threat of terrorism, it only makes sense that the NYPD devote significant resources to protect the World Trade Center,” Police Commissioner Raymond Kelly said.

The NYPD's concerns about the risk of truck bomb attacks against landmark sites forced the 2005 redesign of the project's signature Freedom Tower after police said the 1,776-foot skyscraper's open lobby and street proximity made it a likely terrorist target.

The building, which had a cornerstone in place that had to be moved, was delayed by three years and redesigned for millions of dollars.

The timing of the security agreement depends on how quickly the trade center site is rebuilt. All elements of the redevelopment are behind schedule, and Ward expects to make new estimates in September.

An advisory committee will meet regularly to discuss site security. The group is to include representatives from the city, Port Authority and New York and New Jersey governor' offices.

Associated Press writers Sara Kugler and Amy Westfeldt contributed to this report.