WASHINGTON — President Bush threatened Tuesday to veto any attempt to block a deal allowing an Arab company to take over some operations at six major U.S. seaports, despite overwhelming opposition from congressional leaders, governors and mayors.

“This is a company that has played by the rules, that has been cooperative with the United States, a country that's an ally in the war on terror,” Bush said. “It would send a terrible signal to friends and allies not to let this transaction go through.”

But Republican leaders in Congress and elected officials from New York to Miami said the deal with Dubai Ports World, a company owned by the United Arab Emirates, could jeopardize national security. They demanded a detailed review of an agreement that would allow the company to manage several U.S. port terminals.

“We're putting the fox in the chicken coop,” said J. Christian Bollwage, Democratic mayor of Elizabeth, N.J., which shares with Newark one of the ports to be overseen by the Dubai-based company.

The U.S. government considers the United Arab Emirates a partner in the war on terrorism. But the Maine-sized Persian Gulf nation was a launching point for two 9/11 hijackers. House Homeland Security Chairman Peter King, R-N.Y., said he was “surprised and disappointed” by Bush's veto threat and vowed to “do everything I can to stop this deal from going through” before it goes into effect March 2. Senate Majority Leader Bill Frist, R-Tenn., said he'll introduce legislation to make sure the deal gets more scrutiny because it raises “serious questions regarding the safety and security of our homeland.”

“There's a lot of concern,” said Miami Mayor Manny Diaz, a Democrat. “Maybe some of it is unjustified, but we don't know, we have nothing to judge it on. People deserve to know the facts.”

The $6.8 billion arrangement gives the company management rights to some terminals at ports in New York, New Jersey, Philadelphia, Baltimore, New Orleans and Miami. Those terminals are now run by a British company.

The Homeland Security Department, which controls security at U.S. ports, was among 12 agencies that approved the deal as part of a Treasury department panel that reviews potential foreign investments.

Despite heightened security since 9/11, fewer than 10% of cargo containers unloaded at the nation's busy ports are inspected, according to the Homeland Security Department. As a result, some members of Congress consider ports as vulnerable points of entry for terrorists trying to smuggle weapons into the USA.

Clay Lowery, an assistant secretary at Treasury, said the Dubai deal “did not raise undue concerns about national security.” Bush has nominated one of the company's former executives, David Sanborn, to run the Transportation department's Maritime Administration, which oversees some port operations.