WASHINGTON (AFP) - A man who opened fire on the White House with an assault rifle after telling friends he was on a mission from God to kill United States (US) President Barack Obama was jailed for 25 years on Monday.

Oscar Ramiro Ortega-Hernandez drove more than 3,200km to the US capital from his home in Idaho to carry out his November 2011 attack.

Prosecutors said he fired at least eight rounds at the White House after telling friends he was "on a mission from God to take out" Mr Obama.

Mr Obama and his family were not staying at the White House at the time, and no one was injured in the incident.

Ortega-Hernandez, 23, pleaded guilty in September to terror and weapons charges.

In addition to his jail term, Ortega-Hernandez was ordered to pay US$94,000 (S$118,000) in restitution for damage done to the White House by his attack. He faces five years of supervised release when he leaves prison.

"This man drove cross-country to launch an assault rifle attack on the White House," US Attorney Ronald Machen said in a statement.

"He was motivated by hatred for the President and the desire to start a revolution against the federal government.

"This 25-year prison sentence demonstrates that anyone who comes to the nation's capital planning to use violence should expect to spend decades behind bars."

Ortega-Hernandez was arrested in Indiana, Pennsylvania less than a week after his attack.

According to the Justice Department, Ortega-Hernandez had made repeated anti-government statements beginning in 2010, branding Mr Obama "the devil" and "the anti-Christ", while later describing himself as a "cold-hearted warrior of God".