President-elect Barack Obama boards his plane in Washington January 16, 2009. REUTERS/Jim Young

WASHINGTON (Reuters) - Authorities on Friday arrested a U.S. man on suspicion of threatening to kill President-elect Barack Obama based on statements he posted on a website about UFOs and aliens, the Justice Department said.

Steven Joseph Christopher, in three postings to www.alien-earth.org, said he planned to assassinate Obama in Washington “as a sacrificial lamb,” the department said in a statement.

“It’s really nothing personal about the man. He speaks well ... . But I know it’s for the country’s own good that I do this,” Christopher reportedly wrote.

“It’s not because I’m racist that I will kill Barack, it’s because I can no longer allow the Jewish parasites to bully their way into making the American people submit to their evil ways.”

Christopher added that he needed money to get to Washington and that he did not own a gun, the department said.

Unprecedented security surrounds Obama, who will be sworn into office on Tuesday and become the nation’s first black president.

Christopher, who is from Wisconsin but was arrested in Brookhaven, Mississippi, could face up to five years in prison and a $250,000 fine if found guilty.