WASHINGTON (AP) -- A national missile shield that would offer limited protection from attack by smaller, newly armed countries would cost almost $60 billion through 2015, the nonpartisan Congressional Budget Office (CBO) says.

A CBO report released Tuesday said that's how much would be needed to defend the country from attack by a relatively small number of incoming ballistic missiles. It said those missiles could contain nuclear, biological or chemical weapons, capable of killing millions of people.

The report cautioned that many still believe hostile countries just developing long-range missiles, such as North Korea or Iran, could find easy ways to outmaneuver the proposed defense system.

"It is far too soon to evaluate the overall feasibility or advisability of the missile defense project," he said.

But Rep. Curt Weldon (R-Pennsylvania), a chief proponent of a missile defense system, said the CBO estimate was far too high and has "no basis in reality."

"You can't put a price on protecting American cities," Weldon said, but $60 billion was "totally out of line, out of synch with anything I've seen."

Congress last year passed by large majorities, and President Clinton signed, a bill stating it is the policy of the United States to deploy, as soon as technologically possible, a system capable of defending U.S. territory against limited ballistic-missile attack.

The program has had problems with test failures and has met strong opposition from nuclear powers such as Russia and China. Russia says it would violate the 1972 Anti-Ballistic Missile Treaty and threatened to pull out of other arms-reduction pacts if the United States builds the system.

Clinton is to decide this fall, after another Pentagon test of the system in June, whether to continue with plans to have it operating by a target date of 2005.

"The costs are going up, up and away."
     

The CBO said the first phase of a national missile defense would cost $29.5 billion through 2015, $3.9 billion more than the administration has estimated.

It would include locating 100 interceptors in central Alaska, constructing a high-resolution X-band radar and upgrading several existing early-warning radars.

The second phase, to be deployed by 2010 under current plans, would use satellites that could track not only powered-flight missiles but also missiles gliding through space. The third phase would add 150 interceptors, some at a second site currently planned for Grand Forks, North Dakota.

The administration has not yet estimated the cost of the last two phases. The CBO said the second phase would cost another $6.1 billion and the third phase $13.3 billion through 2015. It said another $10.6 billion would be needed for space-based sensors, satellites that share other missions with missile-defense support.

"The costs are going up, up and away," said Daryl Kimball of the Coalition to Reduce Nuclear Dangers, an advocacy group that believes a national missile defense is unlikely to work even against a minimal threat.

"Congress and the American people, once they realize this, will experience a bit of sticker shock," he said.

Advocates of the system insist the cost is justified because the threat is increasing for long-range missile attack from North Korea or a similar potential adversary.

President Reagan in the 1980s proposed the far more ambitious Strategic Defense Initiative, or "Star Wars," a space-based anti-missile system designed mainly to defend against Soviet attack.