The role of Elon Musk's SpaceX in an ambitious new U.S. missile defense system is in question following the dramatic feud last week between the billionaire entrepreneur and President Donald Trump, according to three people familiar with the project.

The Trump administration has initiated a formal review of SpaceX’s multi-billion dollar contracts following Elon Musk’s public criticism of President Trump. The move raises concerns over political interference in defence spending and national security planning.