WASHINGTON ¨C The United States and Japan say the first live-fire test of Raytheon Co.¡¯s new Standard Missile-3 (SM-3) Block IIA missile, under joint development by the two countries, was a success.

Rick Lehner, a spokesman for the U.S. Missile Defense Agency, said the test was conducted Saturday from the Point Mugu Sea Range off the coast of California.

The SM-3 IIA is a 21-inch variant of an earlier SM-3 missile, which works with the U.S. Aegis combat system built by Lockheed Martin Corp. to destroy incoming ballistic missile threats in space.

The project¡¯s cost is estimated at around $2 billion.

Riki Ellison, who heads the nonprofit Missile Defense Advocacy Alliance, said the two countries will spend about $1 billion each to design, test and eventually produce the new missiles, a model for joint weapons development programs.

¡°It is the U.S. Department of Defense¡¯s best case of equal funding and engineering shared with an allied country to develop and . . . field a new weapon system to better enhance the national security of both nations,¡± Ellison said in a statement.

Raytheon said the new SM-3 IIA missile has bigger rocket motors and a more capable kill vehicle that will allow the missile to engage threats sooner and protect larger regions from short- to intermediate-range ballistic missile threats.

Saturday¡¯s test evaluated the performance of the missile¡¯s nose cone, steering control and the separation of its booster, and second and third stages. No intercept was planned, and no target missile was launched, U.S. and company officials said.

¡°The success of this test keeps the program on track for a 2018 deployment at sea and ashore,¡± said Taylor Lawrence, president of Raytheon¡¯s missile systems business.

Ellison said three more years of testing are planned for the missile before it was put to use on U.S. Navy Aegis ships, Japan¡¯s Kongo-class ships, and at land-based Aegis Ashore sites in Poland and Romania.