Israel's newest missile defense system, designed to provide another layer of protection against enemy fire, is on schedule for deployment in 2014, defense officials said Tuesday.

The "David's Sling" system, named after the famous weapon in the biblical David and Goliath story, is part of a multi-layered defense against incoming rockets and missiles. Two of the elements are operational.

Last year, Israel activated a system that intercepts rockets fired from short distances of up to 70 kilometers (50 miles). Israel says "Iron Dome" has shot down dozens of rockets launched from the Gaza Strip, including several fired over the past week, with 80 percent effectiveness.

Israel has also deployed the "Arrow," a joint Israel-U.S. system meant to shoot down longer range missiles fired from Iran. The next generation of the Arrow, now in the development stage, is set to be deployed in 2016.

The next generation, called the Arrow 3, will strike its target outside atmosphere, intercepting missiles closer to their launch. Together, the two Arrow systems will provide two chances to strike down incoming missiles.

Israel also uses U.S.-made Patriot missile defense batteries against medium-range missiles.

Israel has identified missile defense as a top priority, based on wartime experiences. In the first Gulf War 20 years ago, Iraq fired 39 Scud missiles toward Israel. Patriots failed to hit any of them.

Over the past decade, militants in the Gaza Strip have fired thousands of rockets into Israel. Also, during a monthlong war in 2006, Hezbollah guerrillas in Lebanon launched some 4,000 rockets and missiles into the Jewish state.

Israeli defense officials believe the threat is growing. Israel's military intelligence chief earlier this year estimated that 200,000 enemy missiles and rockets are aimed at Israel.

Hamas militants in Gaza, who once produced rudimentary rockets on their own, now have thousands of foreign-made rockets capable of striking as far away as Tel Aviv, the military said. The Lebanese Hezbollah's arsenal is believed to be even more formidable, including sophisticated Iranian-made guided missiles that can hit anywhere in Israel.

Iran has developed missiles that can travel 2,000 kilometers (1,200 miles), putting Israel well within its range. Israeli concerns have been compounded by the belief that Iran is also developing nuclear weapons, dismissing Iranian denials.

David's Sling, developed by Israel's Rafael Advanced Defense Systems and U.S.-based Raytheon Co., is designed to intercept projectiles with ranges of up to 300 kilometers (180 miles), said a Rafael official at the company plant in Carmiel, northern Israel.

"We'll be able to intercept threats at high altitude in enemy territories, not exactly over Israel," said the official, who spoke on condition of anonymity under company guidelines. "We don't want it falling on us, but over the enemy."

An Israeli defense official familiar with the system said it has passed a number of preliminary tests, but it has not yet undergone a live interception drill. He said it is on schedule to be deployed in 2014.

Uzi Rubin, a former head of Israel's missile defense program, said the system will fill a "significant gap" in Israel's air defenses by protecting against many of the medium range missiles in Hezbollah and Syrian arsenals. It can also be deployed against low flying cruise missiles fired from longer distances.

"Once we finish David's Sling and Iron Dome and the Arrow, then we'll have the most advanced capability available to give a multilayer protection to Israeli citizens," said the defense official, speaking on condition of anonymity because he was discussing classified information.