Tensions have been growing in the region following international condemnation over Tehran's growing nuclear ambitions.
Last month, Britain's ambassador to Iran was expelled from the country following attacks on the British Embassy. The US is also involved in a standoff over a downed spy drone, which President Mahmoud Ahmadinejad has refused to return despite America's requests.
General Martin Dempsey, chairman of the US joint chiefs of staff, said that the US military had reached a point where they were ready to execute force against Iran if necessary.
In an interview with US media in Afghanistan he said: "We are examining a range of options. I'm satisfied that the options that we are developing are evolving to a point that they would be executable if necessary."
His comments come just days after Leon Panetta, US secretary of defence, said "no options were off the table" in stopping Iran develop a nuclear weapon.
Gen Dempsey said he had been quietly leading behind the scenes preparations for an attack against Tehran but said a war with the nation would be a "tragedy".
"My biggest worry is that it may miscalculate our resolve. Any miscalculation could mean that we are drawn into conflict and that would be a tragedy for the region and the world," he said.
Asked whether the US military is collecting information on the Middle Eastern nation via spy drones, Gen Dempsey said it would be "imprudent" for them not to attempt to find out what they were doing but stopped short of saying they had used unmanned aircraft.
"If you are asking are we gathering intelligence against Iran in a variety of means, the answer is of course," he said. "It would be imprudent of us not to understand what a nation which has declared itself an adversary of the United States is doing."
Gen Dempsey said the US is collaborating with Israel in its intelligence gathering but reiterated that there are no guarantees the Israelis would inform the US before launching an attack.
"We are trying to establish some confidence on the part of the Israelis that we recognise their concerns and are collaborating with them on addressing them," he said.
Leon Panetta, the secretary of defence, said this week that the US was prepared to step in to prevent Tehran realising its nuclear ambitions. He estimated that the country was only a year away from reaching its goal.
"The United States does not want Iran to develop a nuclear weapon," he said. "That is a red line for us and that is a red line for the Israelis. If we have to do it we will do it. If they proceed and we get intelligence that they are proceeding in developing a nuclear weapon then we will take whatever steps necessary to stop them. There are no options that are off the table."
If Iran were to gain a nuclear weapon, it could trigger a nuclear arms race in the Middle East with officials in Saudi Arabia already saying they will look towards developing nuclear capabilities if the Iranians arm themselves.
Further evidence of US reconnaissance missions in the region include the indictment of several alleged CIA spies.
In May this year, Iran's intelligence ministry announced the arrest of 30 CIA "spies" it claimed were conducting sabotage missions.
Another 15 alleged US-Israeli spies were indicted earlier this month and this week Iranian state television showed clips of ex-US Marine Amir Hekmati allegedly confessing to espionage.
Earlier this month, the EU agreed to impose new sanctions against 180 officials in Tehran in an attempt to curtail the nation's nuclear programme. EU foreign ministers also said they were looking at additional measures to impose on Tehran's energy sector.