The Bush administration says it will not comment on reports it is considering a naval build-up off the coast of Iran. The reports began to surface as Iranian leaders vowed to defy any international sanctions relating to Tehran's nuclear ambitions. VOA's Paula Wolfson has more on the story.

News organizations in the United States are quoting unnamed defense department officials as saying the Pentagon is considering a buildup of U.S. Navy forces in the Gulf.

When asked about the reports, Bush administration spokesmen refused direct comment.

At the Pentagon, spokesman Brian Whitman said the navy moves ships when necessary, but does not talk about specific moves, plans and contingencies.

Tony Snow

White House press secretary Tony Snow sounded a similar theme.

He said, "We do not comment on tactical moves, reported or otherwise."

Snow was asked if the administration might try to use a military buildup to send a message to Tehran that its support for extremists in neighboring countries must stop, and its uranium enrichment activities must cease.

"Let there be no mistake what our position is toward the Iranians," he said. "But again, when it comes to describing any ongoing military activity, you bet it is not something that I am going to do."

There is already one American aircraft carrier in the region, the USS Dwight David Eisenhower. It arrived a few months ago, part of a flotilla sent to the area to support operations in Iraq and Afghanistan.

At about the same time, the United States led a six-nation naval training exercise aimed at blocking the smuggling of nuclear weapons in the Gulf.

Although it has never ruled out military action, the Bush administration has been putting the focus on diplomacy in its efforts to change Iran's behavior.

Negotiations are under way with members of the U.N. Security Council on a possible sanctions package designed to convince Iran to suspend uranium enrichment, which can produce nuclear fuel for civilian or military purposes.

Iran claims it is pursuing the technology for peaceful purposes, to meet the nation's energy needs. But the United States and many of its allies stress Iran has large oil reserves, and wants to build a nuclear arsenal.

Iranian President Mahmoud Ahmadinejad said Tuesday that U.N. sanctions would not stop his country from pursuing its uranium enrichment program. He warned Britain, France and Germany that Tehran will consider their support for sanctions to be an act of hostility. However, he did not say exactly how Iran might retaliate.