WASHINGTON (Reuters) - U.S. Democratic presidential candidate Hillary Clinton said on Sunday that Russian intelligence services hacked into Democratic National Committee computers and she questioned Republican rival Donald Trump’s overtures to Russian President Vladimir Putin. “We know that Russian intelligence services hacked into the DNC and we know that they arranged for a lot of those emails to be released and we know that Donald Trump has shown a very troubling willingness to back up Putin, to support Putin,” Clinton said in an interview with “Fox News Sunday.” The White House has declined to speculate on who was behind the hack of Democratic Party computers, referring to an ongoing investigation by the Federal Bureau of Investigation. Cybersecurity experts and U.S. officials, however, said they believed Russia engineered the release of the emails to influence the Nov. 8 U.S. presidential election.  Reuters reported a computer network used by Clinton’s campaign was hacked as part of the broad cyber attack on Democratic political organizations. The United States would not tolerate that from any other country, especially one considered an adversary, Clinton said. “For Trump to both encourage that and to praise Putin  despite what appears to be a deliberate effort to try to affect the election I think raises national security issues,” she said. Asked if she believed Putin wanted Trump in the White House, Clinton said she was not going to jump to that conclusion. “But I think laying out the facts raises serious issues about Russian interference in our elections, in our democracy,” Clinton told Fox in the interview, taped on Saturday. The Republican presidential nominee has praised Putin, saying he was a stronger leader than U.S. President Barack Obama, a Democrat. Trump last week invited Russia to dig up tens of thousands of “missing” emails from Clinton’s time at the U.S. State Department. “Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing,” Trump told reporters. He later said he was being “sarcastic” in his comments, which raised concerns among intelligence experts and criticism that Trump was urging a foreign government to spy on Americans. Senator Jeff Sessions, a supporter of Trump, criticized  Clinton for leaving her email system vulnerable to Russian penetration and defended Trump’s comments. “I have people come up to me all the time and say ‘Why don’t you, if you want to find out where those 30,000 emails are, why don’t you ask the Russians?” Sessions told CNN.  WikiLeaks founder Julian Assange refused to answer questions on Sunday about whether a foreign government leaked the DNC emails to the group. “It’s an interesting speculative question for the press,” he told NBC’s “Meet the Press.” Trump’s “absolute allegiance to a lot of Russian wish-list foreign policy positions” is among the reasons he is unfit to be commander in chief, Clinton, a former U.S. senator, secretary of state and first lady, said in the Fox interview. Trump alarmed allies this month when he indicated he might abandon NATO’s mutual defense guarantee in the face of potential Russian aggression if members had not paid their bills. He also  suggested he would consider easing sanctions on Russia and recognizing its annexation of Ukraine’s Crimea region. On Sunday, Trump referred to that annexation again in a way that appeared to justify it. “The people of Crimea, from what I’ve heard, would rather be with Russia than where they were,” he said on ABC’s “This Week.” He also said Putin was “not going to go into Ukraine,” prompting a rebuke from Clinton adviser Jake Sullivan. “Russia is already in Ukraine. Does he not know that?” Sullivan said in a statement. Trump often speaks wistfully about smoother relations between Washington and Moscow. “Having a good relationship with Russia is a good thing, not a bad thing,” he said on ABC. Such comments often leave his campaign to try to toughen the rhetoric. “I think Mr. Trump has made it very clear he views Russia to be somebody that we need to be firm with,” campaign manager Paul Manafort said on CBS’ “Face the Nation.” 