JERUSALEM - The United States and Israel are ready for their largest ever bilateral air defense exercise, aiming to improve the missile defense of Israel, senior US and Israeli military officials said Wednesday.

More than 1,000 American troops will be deploying in the next few weeks alongside Israeli army counterparts at radar and air-defense sites scattered throughout Israel and offshore in a massive drill dubbed, "Austere Challenge 12," Lt. Gen. Craig Franklin, a regional defense commander for the US European Command (EUCOM), told reporters via telephone from an air base in Germany.

During the conference call, both Franklin and Israel Defense Forces (IDF) Brig.-Gen. Nitzan Nuriel declined to give an exact date for the drill, the sixth of its kind, for security reasons.

The complex simulation, which Israeli media reported earlier would commence next week and last up to three weeks, is expected to test both nations' combined air-defense abilities to protect the Jewish state.

However, Franklin, who heads the American side of the equation, denied reports that the test was, in part at least, meant to be a combined show of force meant for either US or Israeli upcoming elections, or to deter Iran from considering any possible attack on Israel.

"This exercise is purely about improving combined US-Israeli military capability," Franklin said, adding that it "is not related to any national elections nor any perceived tensions in the Middle East."

In total, some 3,500 US troops will take part in the drill, which will range from the European theater to US naval craft along Israel's shore, and on land to Patriot 3, Arrow II, Iron Dome and David's Sling missile interceptors arrayed in batteries across Israel.

A US Navy cruiser packing an Aegis naval ballistic missile defense system will serve as command and control for the event, Franklin said. The system is also networked via a series of radar sites, stretching from Israel's upper Galilee near Lebanon, down to its Negev desert.

"The scenario is going to be with threats from all the fronts," Nuriel said, noting that the test would include live fire, in addition to the computer ballistic rocket modeling, as well as hardware and software testing.

Referring to a Hezbollah-sent drone that overflew southern Israel last Saturday until Air Force jets shot it out of the sky, Nuriel said the combined forces had also planned to test reactions to such a flight.

"As part of the scenario, we are going to let the forces deal with this kind of threat, as well," Nuriel said. "We did not need the real event in order to plan against it -- it's part of the plan."

Originally scheduled for April, the joint war game was postponed at the request of Israeli Defense Minister Ehud Barak, who cited budget constraints at the time.

IDF spokesman Capt. Roni Kaplan told Xinhua last week that the exercises are part of a long-standing strategic Israeli-US partnership and "are planned in advance and designed to improve the interoperability of our defense systems."

However, speculations were running high that the delay was a result of the deepening rift between Jerusalem and Washington on how to deal with Iran's nuclear program.

In 2010, Israel and EUCOM held a similar, albeit smaller, air defense drill, code-named Juniper Cobra 10, which involved a combined 2,800 troops and was hailed as a success by both sides.