In the latest case on Wednesday, an upgraded version of the Arrow II - a system already in use - was tested off the coast of California, but communication glitches between the missile and the radar led U.S. defense officials to cut the test short before an intercepting missile could be fired, they said.
They spoke on condition of anonymity because they were not authorized to disclose details of the tests.
The Arrow is part of a multilayered missile defense system Israel is working on to protect it from all forms of missile attack, ranging from short-range rocket fire from Lebanon and the Gaza Strip to longer-range threats from Iran.
State-run Israel Aerospace Industries Ltd. is producing the Arrow together with Chicago-based Boeing Co.
Israeli Defense Ministry spokesman Shlomo Dror said tests of the same Arrow system in Israel earlier this year were "very successful." The tests in the U.S. were designed to allow for greater distances than would be possible in Israel, Dror said. He said malfunctions of systems still in their experimental stage were to be expected and said other tests were called off on Friday and Monday.
The defense officials said the improved Arrow II was meant to intercept a dummy Iranian Shihab missile, which is capable of carrying a nuclear warhead. But U.S. officials blocked the launch of an intercepting missile because of the communications glitch, the Israelis said.
Iran's Shihab-3 has a range of up to 1,250 miles (2,000 kilometers), putting Israel well within striking distance.
Israel sees Iran as its biggest threat, because of its nuclear program and development of medium-range ballistic missiles. Those fears have been compounded by Iranian President Mahmoud Ahmadinejad's persistent anti-Israeli rhetoric.
Israel, like many in the international community, rejects Iran's claims that its nuclear program is only to produce energy.
An operational version of Arrow 2 is partially deployed, and the U.S. and Israel are in the preliminary stages of developing an upgraded Arrow 3.
The homegrown "Iron Dome" system is designed to bring down short-range rockets of the kind Palestinian and Lebanese militants use. Last week, Israeli officials reported a successful live test of Iron Dome.
The Arrow project was spurred largely by the failure of the U.S. military's Patriot missiles to intercept Iraqi Scud rockets that struck Israel in the 1991 Gulf War.