President Obama spoke this morning on the administration's change to a planned European missile defense system, saying the new strategy "will provide stronger, smarter and swifter defenses of American's forces and American allies."

Obama said he made the change after an assessment of the missile defense strategy and unanimous recommendations from Defense Secretary Robert Gates and the Joint Chiefs of Staff. He said the new plan is based around changing intelligence about the threat from Iran's ballistic missile program and developing defense technology.

The new architecture "best responds to the threats we face and utilizes technology that is both proven and cost-effective," Obama said in brief remarks in the White House.

Gates also spoke from the Pentagon, along with Gen. James Cartwright, vice chairman of the Joint Chiefs.

The system will "enhance our ability to respond to the most immediate threats to the Continent as well as future threats," Gates said. He said the plan would be implemented in phases. The first will involve missile defense systems placed on ships; the second, starting around 2015, will move to land-based versions in the Czech Republic and Poland.