Israel and the United States are to hold a joint missile defence exercise, the Israeli military said late on Thursday.

Although the exercise, codenamed "Austere Challenge 12" comes at a time of spiralling regional tensions over Iran's suspected nuclear arms programme, the army said the manoeuvres were planned in advance.

"The exercise scenario involves notional, simulated events as well as some field training and is not in response to any real-world event," the military said in a written response to an AFP query

"The US European Command and the Israel Defence Forces periodically conduct routine exercises in Israel. These exercises, which are part of a long-standing strategic partnership, are planned in advance and part of a routine training cycle designed to improve the interoperability of our defence systems."

It did not say when the exercise would take place.

Local media said that it would get underway in the spring and would be the biggest ever joint manoeuvres between the two allies.

Israel and the United States have a longstanding strategic alliance and are jointly developing the Arrow anti ballistic missile system.

In November the Jewish state staged a major civil defence drill in the Tel Aviv region aimed at simulating a response to conventional and non-conventional missile attacks.

Although Iran says its nuclear programme is for civilian use only, the international community believes it is striving to acquire nuclear arms and Israel says that it is a prime target of the Islamic republic.

Iran has threatened to close the strategic Strait of Hormuz, through which 20 percent of the world's oil flows, if it is hit with sanctions, and has warned the United States not to send an aircraft carrier back into the Gulf.

Last week it test-fired three missiles during war games east of the strait at the entrance to the Gulf.