* Pentagon plan revised with eye on Iran
* Includes "proven" sea-based, land-based missile shields
* Bush-era plan would have covered only 75 pct of Europe
By Jim Wolf
WASHINGTON, April 15 (Reuters) - U.S. anti-ballistic missile systems will cover all of Europe by 2018, a senior Pentagon official said, laying out an ambitious target for defending against a perceived threat from Iran.
"One hundred percent," Bradley Roberts, deputy assistant secretary of defense for nuclear and missile defense policy, said in reply to a question at a hearing of a House of Representatives Armed Services subcommittee Thursday.
Roberts said the Obama administration was putting "proven" sea-based and land-based missile shields into Europe as quickly as possible as part of a revised shield announced last September to any Iranian ballistic-missile strike.
Full coverage of NATO territory in Europe would be achieved around 2018, he said, when a second land-based site is to be established in northern Europe for updated Raytheon Co (RTN.N) Standard Missile-3 missile interceptors.
The Pentagon dubs this Phase 3 of its new "adaptive" missile-defense plans, a continued bone of contention with Russia.
In running through the timeline, Roberts misspoke to the panel, referring to Phase 3 as starting in roughly 2015, rather than the 2018 timeframe as correct, said Navy Commander Bob Mehal, a Pentagon spokesman.
The United States says the multibillion-dollar effort is designed to defend against Iranian short- and medium-range missiles that could be tipped with chemical, biological or nuclear warheads.
Iran could produce enough bomb-grade fuel for a nuclear weapon in as little as one year but would probably need three to five years to deploy a "usable" one, two top U.S. generals told Congress on Wednesday.
President Barack Obama decided last year to scrap a Bush-era plan to deploy a longer-range missile-defense system in Poland and the Czech Republic. Instead, he opted for the phased approach as better matched to the assessment of Iran's capabilities.
The Bush plan, featuring 10 two-stage Boeing Co (BA.N) ground-based interceptors that would have gone to Poland, would have provided only 75 percent coverage of Europe.
"We heard immediately from vulnerable allies in the ... 75 percent equation, those left out, that they were looking for protection," Roberts said in reply to Michael Turner of Ohio, the top Republican on the Strategic Forces subcommittee.
"We wanted to meet their demands for protection and scale the capability as the threat evolves and as our capability improves," Roberts added.
Mehal, the spokesman, said the United States will seek seek "appropriate cost and/or burden sharing" in building out the layered shield.
The United States is discussing the potential location of a forward-based Raytheon AN/TPY-2 radar station it wants to deploy in southern Europe by the end of next year, Roberts said. Phase 1 of Obama's plan also involves ships equipped with Lockheed Martin Corp (LMT.N) Aegis combat systems built for missile defense and SM-3 interceptors.
In the second phase, from roughly 2015, improved interceptors and sensors are to be employed along with an initial land-based SM-3 site somewhere in southern Europe.
The last two phases would produce new generations of SM-3 missiles, co-developed with Japan and deployed on land and at sea, with greater speed and range for coverage of all of Europe and enhanced defense of U.S. soil.
Lieutenant General Patrick O'Reilly, director of the Pentagon's Missile Defense Agency, told the panel that the ground-based interceptors due to have gone to Poland would have cost $70 million apiece vs. $10 million to $15 million for the SM-3 interceptors. (Reporting by Jim Wolf; Editing by Gary Hill)