WASHINGTON — In the weeks after he became the Republican nominee on July 19, 2016, Donald Trump was warned that foreign adversaries, including Russia, would probably try to spy on and infiltrate his campaign, according to multiple government officials familiar with the matter.
The warning came in the form of a high-level counterintelligence briefing by senior FBI officials, the officials said. A similar briefing was given to Hillary Clinton, they added. They said the briefings, which are commonly provided to presidential nominees, were designed to educate the candidates and their top aides about potential threats from foreign spies.
The candidates were urged to alert the FBI about any suspicious overtures to their campaigns, the officials said.
The Clinton campaign didn't respond to a request for comment.
The briefings were led by counterintelligence specialists from the FBI, the sources said. They were timed to occur around the period when the candidates began receiving classified intelligence, the officials said, which put them at greater risk for being targeted by foreign spies. Trump's first intelligence briefing as Republican nominee was Aug. 17, 2016, sources told NBC News at the time.
Trump was "briefed and warned" at the session about potential espionage threats from Russia, two former law enforcement officials familiar with the sessions told NBC News. A source close to the White House said their position is that Trump was unaware of the contacts between his campaign and Russians.
"That the Republican and Democrat nominee for president received a standardized briefing on counterintelligence is hardly a news story," said Raj Shah, a White House spokesman. "That NBC News hears about the contents of this classified conversation due to an inappropriate leak is a news story."
It's unclear whether the warning about Russia was passed on to other campaign officials.
Still, the revelation that the Trump campaign was warned about spying threats from Russia and other adversaries, which has not been previously reported, casts a new light on the Trump campaign's dealings with Russians in the months before the November election.
As a former senator and secretary of state, Clinton would have been familiar with counterintelligence briefings, having already held a top-level security clearance. Trump, who was in his first political campaign, may have been hearing some of the information for the first time.
Trump would have been told, "If you see these kinds of contacts please let us know about them so we can keep you updated on the threat picture," said Frank Montoya, a former FBI counterintelligence agent and supervisor who retired in 2016.
The situation was complicated by the fact that the FBI had already become aware of contacts between members of the Trump campaign and Russia, and was beginning to investigate further. Former CIA Director John Brennan has said he told the FBI about a pattern of contacts the CIA observed between members of the Trump team and Russians, and former FBI Director James Comey said the bureau then began investigating in July 2016.
Montoya and other former FBI officials told NBC News the FBI would not have wanted to compromise that investigation by saying too much in the counterintelligence briefing of Trump.
By the time of the warning in late July or August, at least seven Trump campaign officials had been in contact with Russians or people linked to Russia, according to public reports. There is no public evidence that the campaign reported any of that to the FBI.
After the FBI warning, the candidate's son, Donald Trump Jr., exchanged Twitter messages in September with Wikileaks, which the U.S. intelligence community publicly accused in October of acting as an agent in Russia's covert operation to interfere in the election.
For example, on Sept. 20, WikiLeaks wrote to Trump Jr. that "a PAC run anti-Trump site putintrump.org is about to launch," according to messages first published by the Atlantic magazine. "The PAC is a recycled pro-Iraq war PAC. We have guessed the password. It is 'putintrump.' See 'About' for who is behind it. Any comments?"
The next morning, the Atlantic reported, Trump Jr. responded to WikiLeaks. "Off the record I don't know who that is, but I'll ask around. Thanks."
Trump Jr.'s lawyer, Alan Futerfas, did not dispute the Atlantic's reporting.
