The current and former officials agreed to discuss the intelligence only on the condition of anonymity because much of it remains highly classified, and they could be prosecuted for disclosing it. 
 
 Last week, CNN reported about intercepted phone calls during which Russian officials were bragging about ties to Mr. Flynn and discussing ways to wield influence over him. 
 
 In his congressional testimony, Mr. Brennan discussed the broad outlines of the intelligence, and his disclosures backed up the accounts of the information provided by the current and former officials. 
 
 “I was convinced in the summer that the Russians were trying to interfere in the election. And they were very aggressive,” Mr. Brennan said. Still, he said, even at the end of the Obama administration he had “unresolved questions in my mind as to whether or not the Russians had been successful in getting U.S. persons, involved in the campaign or not, to work on their behalf again either in a witting or unwitting fashion.” 
 
 Mr. Brennan’s testimony offered the fullest public account to date of how American intelligence agencies first came to fear that Mr. Trump’s campaign might be aiding Russia’s attack on the election. 
 
 By early summer, American intelligence officials already were fairly certain that it was Russian hackers who had stolen tens of thousands of emails from the Democratic Party and Hillary Clinton’s campaign. That in itself was not viewed as particularly extraordinary by the Americans — foreign spies had hacked previous campaigns, and the United States does the same in elections around the world, officials said. The view on the inside was that collecting information, even through hacking, is what spies do. 
 
 But the concerns began to grow when intelligence began trickling in about Russian officials weighing whether they should release stolen emails and other information to shape American opinion — to, in essence, weaponize the materials stolen by hackers. ||||| WASHINGTON (Reuters) - Senior Russian intelligence and political officials discussed how to influence Donald Trump through his advisers according to information gathered by American spies last summer, the New York Times reported on Wednesday, 
 
 File Photo: Retired Army Lt. Gen. Michael Flynn, then-incoming White House national security adviser, speaks at the U.S. Institute of Peace "2017 Passing the Baton" conference in Washington, U.S., January 10, 2017. REUTERS/Yuri Gripas/File Photo 
 
 Citing three current and former U.S. officials familiar with the intelligence, the newspaper said the conversations focused on Paul Manafort, then the Trump presidential campaign chairman, and Michael Flynn, a retired general who was then advising Trump. 
 
 U.S. congressional committees and a special counsel named by the Justice Department this month are investigating whether there was Russian interference in the 2016 U.S. election and the possibility of collusion between Trump’s campaign and Russia. 
 
 The controversy has engulfed Trump’s young administration since he fired FBI Director James Comey two weeks ago amid the agency’s investigation of possible Russia ties. Moscow has repeatedly denied the allegations and Trump denies any collusion. 
 
 The New York Times report was the latest indication of the depth of concerns within the U.S. intelligence community about Russian efforts to tip November’s election toward Trump as he battled Democrat Hillary Clinton. 
 
 On May 18, Reuters reported that Flynn and other advisers to Trump’s campaign were in contact with Russian officials and others with Kremlin ties in at least 18 calls and emails during the last seven months of the 2016 presidential race, citing current and former U.S. officials. 
 
 On Tuesday, former CIA Director John Brennan told lawmakers he had noticed contacts between associates of Trump’s campaign and Russia during the campaign and grew concerned Moscow had sought to lure Americans down “a treasonous path.” 
 
 In its report, the New York Times said some Russians boasted about how well they knew Flynn, who was subsequently named Trump’s national security adviser before being dismissed less than a month after the Republican took office. 
 
 Others discussed leveraging their ties to Viktor Yanukovych, the deposed president of Ukraine living in exile in Russia, who at one time had worked closely with Manafort, who was dismissed from Trump’s campaign, the newspaper reported. 
 
 FORMER TRUMP AIDE TO TESTIFY 
 
 Separately, Carter Page, a former foreign policy adviser to Trump’s presidential campaign, told Reuters via text message that he would testify before the House Intelligence Committee but was “still working out details.” 
 
 “Nothing (is) fully confirmed at this stage,” Page wrote, adding that if invited, he would also testify before the Senate Intelligence Committee, but had yet to receive such a request. 
 
 ABC News, which first reported on Page’s planned testimony, said he would testify before the House panel on June 6. A spokesman for the committee declined comment on whether Page would testify. 
 
 In a letter to the panel seen by Reuters, Page accused Brennan of offering a “biased viewpoint” in Tuesday’s testimony. 
 
 On Wednesday morning, the top Democrat on the committee said it would subpoena Flynn in its probe into alleged Russian meddling in the presidential election after he declined to appear before the panel. 
 
 “We will be following up with subpoenas, and those subpoenas will be designed to maximize our chance of getting the information that we need,” Representative Adam Schiff told journalists at a breakfast sponsored by the Christian Science Monitor. 
 
 The leaders of the U.S. Senate Intelligence Committee said on Tuesday they would subpoena two of Flynn’s businesses after he declined to hand over documents in its separate Russia probe. 
 
 Flynn, a retired general, is a key witness in the Russia investigations because of his ties to Moscow. 
 
 He was fired from his position at the White House in February, after less than a month on the job, for failing to disclose the content of talks with Sergei Kislyak, Russia’s ambassador to the United States, and misleading Vice President Mike Pence about the conversations.
– US spies last summer gathered that Russian intelligence officials were discussing how Michael Flynn and Paul Manafort could be used to influence Donald Trump, reports the New York Times. Russians claimed connections to Flynn, a Trump adviser, and discussed using their connections to former Ukrainian president Viktor Yanukovych, a close ally of Vladimir Putin who'd worked closely with Manafort, to sway Trump's campaign chairman, three current and former US officials tell the Times. The intelligence—which didn't reveal direct attempts by Russians to influence either Flynn or Manafort—was passed to the FBI, as was intelligence showing communication between Russian officials and Trump advisers, sources say. It underscores, as the Times puts it, the "increasing understanding of the alarm inside the American government last year about the Russian disruption campaign." Trump advisers, including Flynn, spoke with Russian officials or individuals with Russian ties in 18 phone calls and emails in the seven months before the 2016 election, reports Reuters, citing current and former US officials. Former CIA director John Brennan has said he was aware of intelligence showing contact between Russian officials and Trump advisers, adding it "raised questions in my mind about whether Russia was able to gain the cooperation of those individuals." However, Carter Page, a foreign policy adviser on Trump's campaign who says he plans to testify before the House Intelligence Committee, claims Brennan offers a "biased viewpoint." Trump, Manafort, and Flynn have denied any collusion with Russia.