United States has moved more warships and fighter aircraft to the Persian Gulf to keep the strategic Straits of Hormuz open and strike deep within Iran if the stand-off over its nuclear programme escalates.
Quoting senior American officials, The New York Times said the new deployment to bolster military presence in the gulf is aimed at reassuring Israel that Washington is serious about neutralising Iran's nuclear ambitions.
The reports of US moving new forces to the region came as Tehran announced that it had test-fired a new range of ballistic missiles capable of striking Israel.
Iranian news agency IRNA said Iran's revolutionary guards had fired 2,000 kilometer range Shahab-3 missiles in the Kavir Desert in central Iran as part of its war games designs to show its ability to hit back, if attacked.
IRNA also said that along with the medium range Shahab-3 Iran had also test fired 300-500 kms strike distance Shahab-1 and Shahab-2 missiles.
NYT quoted senior US officials as saying that Washington was determined to keep the strategic waterway open at all costs.
"The message to Iran is, 'Don't even think about it,'" one senior US Defense Department official said.
"Don't even think about closing the strait. We'll clear the mines. Don't even think about sending your fast boats out to harass our vessels or commercial shipping. We'll put them on the bottom of the gulf," the official said.
Times said since late spring, stealth F-22 and older F-15C warplanes had moved into two separate bases in the Persian Gulf to bolster the combat jets already in the region and the carrier strike groups that are on constant tours of the area.
These new deep penetration strike aircraft give the US military greater capability against coastal missile batteries that could threaten shipping, as well as the reach to strike other targets deeper inside Iran.
The American Navy has doubled the number of minesweepers assigned to the region, to eight vessels, in what military officers describe as a purely defensive move.
The Americans have also moved a converted amphibious transport and docking ship, the Ponce, into the Persian Gulf to serve as the Pentagon's first floating staging base for military operations or humanitarian assistance.
The initial assignment for the Ponce, Pentagon officials say, is to serve as a logistics and operations hub for miclearing. But with a medical suite and helicopter deck, and bunks for combat troops, the Ponce eventually could be used as a base for special operations forces to conduct a range of missions, including reconnaissance and counter-terrorism, all from international waters.
Iran has threatened to close the strategic Straits of Hormuz at the entrance to the oil-rich Gulf if its nuclear program is targeted by air strikes.
That threat, repeated since December, helped propel oil prices to a four-year high of $123 for a barrel.
While Iranian vessels have avoided any confrontations with allied warships in recent weeks, Iran expects to equip its ships in the Strait of Hormuz soon with shorter-range missiles, a Revolutionary Guards commander has said.
With an eye on the threat of a belligerent Iran, the US administration is also seeking to expand military ties with the six nations in the Gulf Cooperation Council: Saudi Arabia, Kuwait, Bahrain, Qatar, the United Arab Emirates and Oman.
The United States and 19 other countries will hold a major mine countermeasure exercise in the Persian Gulf in September, said a senior military officer who noted that countries in the region were taking more steps in their own defense, including buying American-made air defense systems and other weaponry.