Donald Trump has received his first classified intelligence briefing, a privilege reserved for US presidential candidates from the two main political parties.
The Republican nominee attended the briefing - organised by the office of the director of national intelligence - in secure rooms of the FBI's New York office, ABC television reported.
Democrat Hillary Clinton is set to receive her briefings separately.
The sessions - designed to prepare candidates for the nation's highest office in the event they win November's general election - provide information about global threats against the United States.
However, Mr Trump received no information about intelligence operations or espionage, NBC reported.
Two of his leading advisors, New Jersey Governor Chris Christie and retired general Michael Flynn - a former director of the Defense Intelligence Agency - also took part.
During an interview with Fox News broadcast late yesterday, Mr Trump said he had scant trust in the US intelligence community delivering the briefings.
"Not so much from the people that have been doing it for our country. Look what's happened over the last ten years. Look what's happened over the years. It's been catastrophic," he told Fox News.
He added that he was unlikely to install some members of the existing security establishment in his presidential administration.
"Very easy to use them. But I won't use them because they've made such bad decisions," he said.
Democrats have raised concerns about whether Mr Trump is fit to receive classified information, including President Barack Obama, who issued a thinly-veiled warning at a news conference earlier this month.
"If they want to be president, they have got to start acting like (a) president," he said in a clear reference to Mr Trump.
"That means being able to receive these briefings and not spreading them around."
Yesterday, Mr Trump overhauled his campaign team for the second time in two months, hiring the head of a conservative new website to bolster his image.
Mr Trump named Steve Bannon, head of the Breitbart News website, as campaign chief executive officer, a new position. He also promoted senior adviser Kellyanne Conway to the post of campaign manager.
The billionaire trails Mrs Clinton in national opinion polls and in many battleground states, potentially facing a big defeat that could also cost Republicans congressional races.
He has since faced a barrage of criticism from Republicans over his campaign style and his refusal to stick to a policy message.
The campaign appointments amounted to a demotion for Paul Manafort, who was brought on as campaign manager in June to bring a more professional touch to Mr Trump's campaign but has struggled to get the businessman to rein in his freewheeling ways.
Mrs Clinton, who has called Mr Trump temperamentally unsuited for the White House, said staff shake-ups did nothing to change the candidate and his rhetoric.
"Donald Trump has shown us who he is, he can hire and fire anybody he wants from his campaign, they can make him read new words from a teleprompter, but he is still the same man who insults Gold Star families, demeans women, mocks people with disabilities and thinks he knows more about ISIS than our generals," she told a rally in Ohio.
The appointment of Mr Bannon suggested Mr Trump was aiming not to tone down his aggressive style but to be more disciplined in emphasising themes that resonate strongly with the voters he is trying to court, such as his tough stance against illegal immigration and withering personal criticism of Mrs Clinton.
"I am who I am, I don't want to change," Mr Trump told Wisconsin television station WKTB on Tuesday. "If you start pivoting, you're not being honest with people."
