The United States and Israel are preparing to stage a major joint missile- and air-defense drill in Israel later this month, an exercise that will showcase the allies’ longtime military partnership as they debate how to handle the Iranian nuclear threat.

About 1,000 U.S. troops are en route to Israel for the drill, in which they and Israeli soldiers will use American and Israeli anti-missile defense systems and a U.S. missile defense ship to respond to simulated attacks from multiple fronts, according to the commanders heading the operation.

The drill comes amid high international tensions over the Iranian nuclear program and a countdown to national elections in both the United States and Israel, whose leaders have sparred over the issue. Israeli Prime Minister Benjamin Netanyahu has led the charge for military action and called on the United States to issue an ultimatum to Iran; the Obama administration has declined to do so and has stressed the need to allow diplomacy and sanctions time to bear fruit.

On Wednesday, the military officials in charge of the drill, U.S. Lt. Gen. Craig Franklin and Israeli Brig. Gen. Nitzan Nuriel, took pains to emphasize that the exercise is the sixth in a series of regularly scheduled bilateral drills. The exercise will be “strictly defensive in nature,” Franklin said in a telephone briefing with reporters.

“AC-12 is not related to any national elections nor any perceived military tensions in the Middle East,” Franklin said, using an acronym to refer to the drill, which has been dubbed Austere Challenge 12. The officials declined to specify the precise start date of the exercise, which is expected to last about three weeks.

“Anybody can get any type of message from this exercise,” Nuriel said. “The fact that we are practicing together and working together is a strong message by itself.”

The exercise also follows signs of possibly escalating military threats to Israel from outside its boundaries. Earlier this month, the head of the Lebanese militant group and political party Hezbollah, which is backed by Iran, said it had launched a drone that the Israeli military shot down over its territory. This week, Israel said that Gaza Strip-based militants had for the first time fired an anti-aircraft missile at an Israeli helicopter.

Iran possesses an arsenal of missiles that could strike Israel, and it has threatened to retaliate against both Israel and the United States in the event of an attack on its nuclear sites.

The drill was originally scheduled for to last spring, but it was canceled at Israel’s behest amid growing speculation of an impending Israeli attack on Iran. The number of U.S. troops slated to participate was also scaled back at Israel’s request, Franklin said.

Even amid occasional flare-ups in political tensions, Israeli and U.S. military officials have said that behind-the-scenes security cooperation and intelligence sharing are stronger than ever.