The authorization for the extra funding was part of a defense spending bill that would provide $726 billion next year for U.S. national defense programs, including funding for the wars in Iraq and Afghanistan. The House gave the bill final passage on Friday by a vote of 229 to 186.

The Senate Armed Services Committee likewise voted to provide $205 million for the Israeli system, known as "Iron Dome," panel chairman Carl Levin told reporters on Friday. Levin said he hoped his committee's bill would reach the Senate floor before the July 4 Independence Day recess.

A congressional staff member said the request for the funding "seems to have come directly from the commander in chief," Obama. It was not entirely clear what prompted it.

Produced by Israeli state-owned Rafael Advanced Defense Systems Ltd., Iron Dome uses small radar-guided missiles to blow up Katyusha-style rockets with ranges of between 3 miles and 45 miles, as well as mortar bombs, in mid-air.

Its development was spurred by the 2006 conflict in Lebanon with Hezbollah, and the Gaza Strip war against Hamas a year ago. In both cases, Israeli towns within reach of short-range rockets were in some ways defenseless.

A White House spokesman, Tommy Vietor, said earlier this month Obama recognized "the threat missiles and rockets fired by Hamas and Hezbollah pose to Israelis."

As a result, he decided to seek funding from Congress to support the production of the Iron Dome system, Vietor said.

Two Iron Dome batteries are under construction, an Israeli defense official said in February. Designed to be towed by vehicle, they will be available for any Israeli front at a few hours' notice.

The Pentagon's Missile Defense Agency has three initiatives with Israel to boost its home-grown capability to defend against short- and medium-range ballistic missiles.

The so-called David's Sling Weapon System is for short-range defense; the Arrow Weapons System targets medium-range missiles; and the Arrow-3 interceptor is an upper-tier system under development.

The United States is also developing interoperability between the U.S. ballistic missile defense system and the Israeli architecture to make sure Israeli systems can be stitched in to a global umbrella.

In addition, the Obama administration is working toward a Middle East missile defense that envisions adding an advanced radar site in a Gulf state to one already in Israel to thwart any Iranian attack, U.S. officials have told Reuters.

The House voted to authorize $10.3 billion for ballistic missile defenses overall, $361.6 million more than Obama's request. The extra funds will strengthen defenses against "the most immediate threats from nations such as Iran and North Korea," said Rep. James Langevin, the Strategic Forces subcommittee chairman.

(Reporting by Jim Wolf; editing by Todd Eastham)