A proposed multibillion-dollar missile defense system for Guam has been reduced to 16 sites on the island from the original 22, the U.S. Missile Defense Agency said in a draft environmental impact statement Friday.

The project is designed to create "360 degree" protection for the U.S. Pacific territory from missile and air attacks of all kinds, the agency said. Plans include integrating Raytheon's SM-6, SM-3 Block IIA, Lockheed Martin's THAAD, and the Patriot PAC-3, which uses components from both companies, over about 10 years.

The environmental impact study, which began last year and included a public comment period this year, proposes "deploying and operating and maintaining a combination of integrated components for air and missile defense positioned on 16 sites" on the island. The report does not say why the number of sites was reduced.