He said that the US naval presence in the Gulf has increased in the past weeks, but would not directly comment on a report that the United States is sending a second aircraft carrier to the Gulf.

"My impression is there has been an increase in naval strength in the Gulf in the past several weeks," he said.

"I don't think it's a response to anything anyone else has done," he said in response to a question on whether the buildup was related to the Iranian nuclear dispute.

As Gates spoke to reporters in front of US military headquarters outside Baghdad, the crackle of gunfire could be heard in the distance.

Gates is wrapping up a three-day visit to Iraq to assess the situation as the US considers changes in strategy there.

US, Britain move ships to Gulf in signal to Iran: report
Washington (AFP) Dec 21 - The United States and Britain will start moving additional ships into the Gulf region in a signal to Iran as the United Nations weighs sanctions action, The New York Times reported Thursday.

"Defense Secretary Robert M. Gates was expected this week to approve a request by commanders for a second aircraft carrier and its supporting ships to be stationed within quick sailing distance of Iran by early next year," the Times quoted unnamed US officials as saying.

Though the US officials said the ships were not part of preparations for an offensive strike, "they acknowledged that the ability to hit Iran would be increased and that Iranian leaders might well call the growing presence provocative."

The British Navy "plans to add two mine-hunting vessels to its ships that already are part of the international coalition patrolling waters in the ... Gulf," the report added.

In Tehran on Thursday, President Mahmoud Ahmadinejad vowed that nothing would stop Iran from pushing ahead with its nuclear program, as world powers prepared for a likely vote that could slap UN sanctions on Tehran.

"The United States and Europeans know well that they cannot do anything against Iran and their pressure will not hold back Iran's desire to fully obtain peaceful nuclear technology," Ahmadinejad said.

"The bullying powers today, in confronting Iran's peaceful nuclear technology, are faced with a sea of courageous people," he said in a speech in the town of Gilan-e Gharb in the western Kermanshah province.

"If they think that nuclear energy only belongs to one group of the Iranian people, they are mistaken," he added.

Ahmadinejad also reaffirmed his prediction that Iran would be able to hold a "nuclear celebration" at the same time as it marks the 28th anniversary of the Islamic revolution on February 11.

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