This is the VOA Special English Economics Report.

Today we continue our report on the group of chemical elements known as rare earth metals. These are mined from the earth and used to make technology from mobile phones to missiles.

The United States once led the world in rare earths. Today China controls almost all production. Premier Wen Jiabao says China will not use these metals as a diplomatic weapon. But Japan says exports meant for that country have remained at Chinese ports as a result of a recent dispute.

The United States stopped mining rare earths in two thousand two. Companies blamed environmental rules and low-priced imports from China. But now exploration is moving forward again.