Washington - Hillary Clinton on Sunday sharply criticised Donald Trump over his "absolute allegiance" to Russian policy aims, saying it raised both "national security issues" and new doubts about his temperament.Trump, her Republican rival in the race for the White House, responded defiantly, saying he had "no relationship" with Russian leader Vladimir Putin and had never met nor spoken to him by phone, but that "if our country got along with Russia, that would be a great thing".He said in an ABC interview that he was not about to disavow it if Putin praised him as a "genius" (some Russian speakers say "colourful" was a better translation of the word).But further fanning controversy, Trump added that as president he would at least consider acknowledging Russian sovereignty over Crimea, the Ukrainian territory that Russia annexed in 2014 in the face of widespread international condemnation."The people of Crimea, from what I've heard, would rather be with Russia," Trump said.The territory was the subject of a head-scratching exchange between Trump and ABC "This Week" host George Stephanopoulos."(Putin's) not going into Ukraine, okay, just so you understand," Trump said. "He's not gonna go into Ukraine, all right? You can mark it down. You can put it down."Stephanopoulos responded: "Well, he's already there, isn't he?"Trump replied, "Okay - well, he's there in a certain way. But I'm not there."Clinton senior policy advisor Jake Sullivan called Trump's statement "scary stuff.""What is he talking about? ... What else doesn't he know?" Sullivan said in a statement. "While Trump hasn't mastered basic facts about the world, he has mastered Putin's talking points on Crimea."Trump said he was not involved in Republicans' softening of their platform language to remove a call to provide Ukraine with lethal weaponry.The dispute over Russia is part of a broader disagreement over US engagement abroad, as Trump argues that a weakened America must retrench and demand greater contributions from its allies, while Clinton asserts that decades-old US commitments to foreign partners must be maintained.Backlash over emails Clinton, in her comments, was responding on "Fox News Sunday" to allegations of Russian involvement in leaks of Democratic Party emails that embarrassed her on the eve of the just-ended Democratic national convention. As that convention was under way, Trump urged Russia to find and release several thousand emails that disappeared from Clinton's private server while she was secretary of state."Russia, if you're listening," Trump said at the time, "I hope you're able to find the 30 000 emails that are missing. I think you will be mightily rewarded by our press."That call, of a sort nearly unprecedented in US presidential politics, drew sharp rebukes from Democrats and some Republicans.US cybersecurity experts said it raised questions about whether Russia had attempted to influence the American campaign in Trump's favor. Leaked emails published by WikiLeaks revealed the distrust of some key Democratic leaders of Bernie Sanders, Clinton's former rival for the Democratic nod.Trump's seeming encouragement of Russian hacking, Clinton told Fox, "raises issues about Russian influence in our election.""And 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."'Not temperamentally fit' When an interviewer noted that Trump had claimed he was being sarcastic, Clinton replied: "If you take the encouragement that Russians hack into email accounts, if you take his quite excessive praise for Putin, his absolute allegiance to a lot of Russian wish-list foreign policy issues," it suggests that "he is not temperamentally fit to be president and commander-in-chief."Trump had earlier unnerved NATO member nations by questioning the long absolute US commitment to defend any member of the Atlantic alliance should it be attacked by Russia.In an interview, with The New York Times just before the Republican convention, Trump said that if Russia attacked NATO member nations he would decide whether to come to their assistance only if he decided that they had "fulfilled their obligations to us."Trump has also said he might withdraw US troops from European and Asian countries if they failed to pay more for American protection."We are going to take care of this country first," he told The Times, "before we worry about everyone else in the world."