Homeland Security Secretary Michael Chertoff is defending a deal giving a company in the United Arab Emirates control over terminals at key U.S. ports. Critics in Congress say the deal is a threat to national security.

Critics have blasted the recent deal, in which government-owned Dubai Ports World purchased London-based Peninsular and Oriental Steam Navigation Company, a private company that runs commercial operations in six major U.S. ports.

The nearly $7-billion sale has been approved by the Committee on Foreign Investment in the United States, which includes officials from the Departments of Commerce, Defense, Homeland Security, Justice, and State.

Homeland Security Secretary Michael Chertoff emphasized that the deal has undergone close scrutiny, although he said he could not provide details.

"Without getting into classified information, what we typically do if there are concerns, is we build in certain conditions or requirements that the company has to agree to to make sure we address the national security concerns," said Michael Chertoff. "And here, the Coast Guard and Customs and Border Protection really played a leading role for our department in terms of designing those conditions and making sure that they are obeyed."

A bipartisan group of senators and House members last week called on the Bush Administration to review the sale, saying it undermines national security.

They noted that the United Arab Emirates served as a base for the hijackers who took part in the September 11, 2001 terrorist attacks on the United States. They also argue that the UAE was one of only three countries that recognized the Taleban as Afghanistan's legitimate government.

The Bush Administration considers the United Arab Emirates an ally in the war on terror.

Secretary Chertoff told NBC's Meet the Press he believes it is not fair to automatically cut off business with entire countries, like the United Arab Emirates, just because there were some UAE connections to the September 11 terrorists. He pointed to the so-called shoebomber, the terrorist who tried to detonate a bomb in his shoe while on an airplane, to make his point.

"Well, Richard Reid was British," he said. "He was going to blow up an airliner. We do not say the British cannot buy companies here."

He added that he believes the committee's careful review of the deal, which includes building safeguards into it, reduces any risks to the United States.

"And this is part of the balancing of security, which is our paramount concern, with the need to still maintain a real robust global trading environment," explained Michael Chertoff.

The six major American ports affected are Baltimore, Miami, New Jersey, New Orleans, New York, and Philadelphia.

The Associated Press reports that a company at the Port of Miami has sued to block the UAE company's takeover of shipping operations there. The company, Continental Stevedoring and Terminals, said it will become an "involuntary partner" of Dubai Ports World. It also expressed doubts that the UAE company, Florida or the U.S. government can ensure compliance with American security rules.