Jeff Sessions, Mike Flynn and Mike Pompeo will have high profile roles
President-elect Donald Trump has picked controversial senator Jeff Sessions to be the next US attorney-general.
Mr Sessions is known for inflammatory statements on immigration and is an enthusiastic backer of Mr Trump's proposal to build a wall at the Mexico border.
The 69-year-old Alabama senator was an early supporter of Mr Trump, endorsing him in the presidential campaign and becoming a close aide.
Mr Trump, who is working on his transition from Trump Tower in New York, also selected General Mike Flynn as national security adviser and representative Mike Pompeo as CIA director.
A transition official said all three have accepted the positions and their nominations would be formally announced later, Reuters reported.
Mr Sessions, a 20-year congressional veteran, could face resistance as he seeks Senate confirmation.
In 1986, he was nominated by then-President Ronald Reagan to be a federal judge, but was denied confirmation after allegations that he had made racist remarks.
Those included testimony that in 1986 he had called an African-American prosecutor "boy" - an allegation Mr Sessions denied.
He said he was not a racist, but said at his hearing that groups such as the National Association for the Advancement of Colored People and the American Civil Liberties Union could be considered "un-American".
A retired US Army three-star general, the 57-year-old Mr Flynn is one of Mr Trump's closest advisers.
In 2012 he was appointed director of the Defense Intelligence Agency (DIA), and quickly built a reputation as an astute intelligence professional and straight talker.
He retired two years later over disagreement with the Obama administration's approach to global affairs and fighting Islamic State militants.
Mr Flynn has urged Washington to work more closely with Moscow, echoing similar statements from the president-elect.
He travelled to Moscow last year to join Russian President Vladimir Putin in a celebration of RT, a television channel funded by the Russian government. He dismissed accusations that he was aiding a propaganda effort.
In a new book Mr Flynn co-authored, he prescribes a harder political line on Iran, including information warfare to expose shortcomings in Iran's revolution.
Colin Powell, the former secretary of state, was disparaging of Mr Flynn in e-mails that were leaked online and reported by BuzzFeed and others.
He called Mr Flynn a "right-wing nutty" and a "jerk", and said he had been forced out of the DIA.
Mr Flynn's position as national security adviser does not require Senate confirmation, but he would work in the West Wing and have frequent access to the new president.
Mr Pompeo, a 52-year-old Kansas congressman, was on the House of Representatives intelligence and energy and commerce committees.
He gained prominence as a member of the congressional committee that blasted Hillary Clinton over the 2011 attack on the US diplomatic mission in Benghazi, Libya.
A conservative Republican, Mr Pompeo enrolled as a teenager in the Military Academy at West Point and graduated first in his class in 1986.
He then graduated from Harvard Law School, where he was editor of the law review.
He has been a fierce critic of Mr Obama's nuclear deal with Iran.
On Thursday, he wrote on Twitter: "I look forward to rolling back this disastrous deal with the world's largest state sponsor of terrorism."
I look forward to rolling back this disastrous deal with the world’s largest state sponsor of terrorism. https://t.co/bifC97jWpY— Mike Pompeo (@RepMikePompeo) November 17, 2016