A top Russian official warned an advanced U.S. missile defense shield move could lead to military "confrontation" in space.

The document titled "The Iron Dome for America" outlines the construction of a "next-generation missile defense shield" and is currently a general directive. Signed by Donald Trump, it requires the Secretary of Defense to present a plan for the defense system to the President within 60 days.

The first Trump administration floated a space weapon concept in March 2018: a neutral particle beam in space. But it ultimately shelved the idea because of the massive amount of power needed to destroy a missile with directed energy.