Britain isn't worried about the proposed sale of a London-based port operator to a Dubai firm, but it will be up to Americans to decide about their own security concerns, British Deputy Prime Minister John Prescott said Wednesday. The proposed sale of the company with shipping operations at six major US ports to a state-owned United Arab Emirates company has prompted opposition by American lawmakers on security grounds, though President George W. Bush has threatened to veto attempts to block the sale. "I think probably the president was right in that, wasn't he? He doesn't think it's a threat to security, but that's for the Americans to make their decision about it," Prescott said during a visit to Beijing. "We are certainly not worried about the change," he said. Brushing aside objections from Republicans and Democrats alike, Bush on Wednesday endorsed the takeover. He pledged to veto any bill Congress might approve to block the agreement. The president on Tuesday defended his administration's earlier approval of the sale of London-based Peninsular and Oriental Steam Navigation Co. to Dubai Ports World, despite concerns in Congress it could increase the possibility of terrorism at American ports. The sale expected to be finalized in early March would put Dubai Ports in charge of major shipping operations in New York, New Jersey, Baltimore, New Orleans, Miami and Philadelphia. "If there was any chance that this transaction would jeopardize the security of the United States, it would not go forward," Bush said. "It sends a terrible signal to friends around the world that it's OK for a company from one country to manage the port, but not a country that plays by the rules and has got a good track record from another part of the world," Bush said. To assuage concerns, the administration disclosed some assurances it had negotiated with Dubai Ports. It required mandatory participation in US security programs to stop smuggling and detect illegal shipments of nuclear materials; roughly 33 other port companies participate in these voluntarily. The Coast Guard also said Tuesday it was nearly finished inspecting Dubai Ports' facilities in the United States. Democratic senators said Monday that US President George W. Bush should stop the deal to better protect the US from terrorists. "We wouldn't turn over our customs service or our border patrol to a foreign government," New Jersey Senator Robert Menendez said during a news conference. "We shouldn't turn over the ports of the United States, either." Menendez said he and Senator Hillary Rodham Clinton would introduce legislation prohibiting the sale of port operations to foreign governments. Lawmakers say they are worried there are insufficient safeguards to thwart infiltration of the vital facilities by terrorists. "It's unbelievably tone deaf politically at this point in our history," Senator Lindsay Graham, a Republican, said on "Fox News Sunday." "Most Americans are scratching their heads, wondering why this company from this region now." Attorney General Alberto Gonzales on Monday defended the deal and said the administration had a "very extensive process" for reviewing such transactions. "Lots of considerations are weighed in connection with a recommendation, and the consensus was this was a transaction that should be approved," he said. "It was something that went through our normal process. It's one that takes into account matters of national security, takes into account concerns about port security. And for a variety of reasons, the consensus was that this was a transaction that should be approved." But critics have cited the UAE's history as an operational and financial base for the hijackers who carried out the attacks of Sept. 11, 2001. In addition, they contend the UAE was an important transfer point for shipments of smuggled nuclear components sent to Iran, North Korea and Libya by a Pakistani scientist. "God, if you have a country that is not doing internally what it should be to prevent the transfer of nuclear parts, we're going to give that country operation of the major ports of this nation?" Menendez asked. "I think not." "It needs to be stopped by the president, first and foremost. Either freeze the deal or negate the deal," he added.