A surge in Palestinian militant rocket attacks from Gaza at Israeli civilian targets, and Air Force counter strikes at launching crews will not impact a massive, bilateral air-defense exercise, generals on both the Israeli and U.S. sides said Wednesday.

At a press conference held alongside a Patriot missile battery deployed in Tel Aviv, U.S. Army Lt-Gen. Craig Franklin, regional air defense commander for European Command (EUCOM), and Israel Defense Forces (IDF) counterpart, Brig.-Gen. Shahar Shohat, both emphasized a "business-as-usual" attitude.

On Sunday, the two armies embarked on the three-week-long " Austere Challenge 12" (AC-12) maneuvers, which simulate responses to simultaneous mass missile attacks on Israel from several fronts.

"Four days ago, we commenced the largest combined defensive exercise ever to take place between the European Command of the United States military and the Israeli Defense Forces," Shohat said, reading from a prepared statement.

Their mannered press conference, held at dusk near trucks and troops manning the rocket battery on a grassy beach fronting expensive rows of apartments, belied the explosive violence taking place some 50 km to the south.

"Make no mistake: the United States is 100 percent committed to the security of Israel," Franklin stressed. "That commitment drives the goal of this exercise, and that is to test and hone our combined ability to defend against missile attacks as we seek to maintain peace through preparedness."

But, Franklin said, the drill "was not related to any specific current events in the region." Both generals repeatedly stressed that the maneuvers, while perhaps serving as a visible deterrent to foes, like Iran and Hezbollah in Lebanon, were two years in the making.

"With the United States, we have the world's best, most state- of-the-art air defense system," Shohat said. "This exercise aims to improve the interaction between the IDF and US military, enhance interoperability, and strengthen the strong relationship we already share."

The command post and field training exercises, computer simulations, and live fire drill will include "over 1,000 U.S. military personnel in Israel, 2,500 outside of Israel, and 1,000 IDF personnel," according to Shohat.

But meanwhile, in and around Gaza, air defenses were anything but simulated.

"The fact that there's real-world operations going on is just a coincidence," Franklin told a reporter.

In the last 48-hours, Palestinian militants have fired close to 80 Grad and Kassam rockets, and mortar shells into Israeli towns and villages in a roughly 10-km arc surrounding the coastal enclave.

Five people were wounded and some seven homes sustained damage in a number of Israeli communities during the intense barrages.

On Wednesday, an Iron Dome battery deployed near Ashkelon, about five km north of Gaza, downed eight rockets aimed at the coastal city.

Israeli Air Force craft dispatched at least four sorties over Gaza to strike areas from where the rockets are being launched, the army said. Palestinian sources said several militants were killed, and close to a dozen people were wounded by the Israeli retaliation.

Earlier, IDF Chief-of-Staff Lt.-Gen. Benny Gantz ordered his forces to cut back the number of troops taking part in AC-12.

The several-week-long drill ranges from the U.S. European Theater to U.S. naval craft deployed along Israel's shoreline, to Patriot 3, Arrow II, Iron Dome and David's Sling missile interceptors arrayed in batteries across the country.

The Israel and U.S. forces -- some 3,500 in all, are trained in switching from simulation mode to genuine air-defense, if necessary, as took place over Ashkelon.

The IDF has "enough Iron Dome batteries to cover areas in danger," army Spokesman Lt.-Col. Avital Leibovich told Xinhua in a conference call Wednesday morning.

"In light of the escalation in the south and the fear of a worsening situation due to the IDF responses, it's important that the IDF be ready for any scenario from Gaza," a military official said during a tour of hard-hit southern communities.

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

However, speculations were running high that a delay in the drill -- to have been held in April -- 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.