New York  - New Yorkers got a clearer picture of the turf wars at the site of the destroyed World Trade Center on Wednesday, the eve of the seventh anniversary of 9/11, with Mayor Michael Bloomberg complaining of indecision and infighting among parties involved in the construction of the site.

Bloomberg insisted on meeting the 2011 completion deadline for the memorial to the nearly 3,000 people killed by terrorist attacks since 1993, complaining that progress to rebuild Ground Zero has been "frustratingly slow."

The destruction of the World Trade Center's twin towers by two hijacked passenger planes on September 11, 2001, killed more than 2,700.

A total of 184 were killed in Washington when terrorists slammed a hijacked commercial airplane against the Pentagon, where a memorial of metal benches is to be dedicated on Thursday.

Others died when a fourth plane commandeered by the terrorists crashed in Pennsylvania after a battle with passengers on board.

"Progress on the redevelopment of the World Trade Center has been frustratingly slow, owing in large part to a multilayered governance structure that has undermined accountability from the get-go," Bloomberg said in the editorial pages of New York newspapers.

"The rebirth of Lower Manhattan will not be completed as long as Ground Zero remains an open wound," he said.

Bloomberg said his administration has agreed with the Port Authority of New York and New Jersey to a joint plan to guard and secure the World Trade Center site, an agreement that "will pre-empt any potential turf wars and allow for a seamless integration of police operations at the site and in the surrounding area."

The authority owns the 16-acre land parcel at Ground Zero, but the World Trade Center is leased to a private real estate company while the city is responsible for streets around the site and security.

The new World Trade Center is expected to cost more than 10 billion dollars and the memorial close to 1 billion dollars.

Bloomberg wants the memorial to be completed by 2011, saying, "No more excuses, no more delays."

On Thursday, politicians, government officials and families of terrorist victims will gather in Lower Manhattan to observe a series of events commemorating the tragic 9/11 event.

Architects and the city on Wednesday unveiled a new design for the memorial, which will evoke the 110-storey twin towers blown up in 2001 by two terrorist-hijacked commercial airplanes. The memorial will have two pools resting on the original footprints of the twin towers, which will be surrounded by oak trees. (dpa)