BRUSSELS, Feb 16 - US President Donald Trump's defense secretary on Thursday said he did not see the conditions for military collaboration with Russia, in a blow to Moscow's hopes for repairing ties with the United States following Trump's election."We are not in a position right now to collaborate on a military level. But our political leaders will engage and try to find common ground," Mattis told reporters after talks at NATO headquarters in Brussels.Asked whether he believed that Russia interfered in US presidential elections, Mattis said: "Right now, I would just say there's very little doubt that they have either interfered or they have attempted to interfere in a number of elections in the democracies."Mattis' remarks came shortly after his Russian counterpart, Sergei Shoigu, expressed readiness to resume cooperation with the Pentagon and the same day Russian President Vladimir Putin said it was in the interests of both nations to restore communications between their intelligence agencies."It's in everyone's interest to resume dialogue between the intelligence agencies of the United States and other members of NATO," Putin said, addressing Russia's Federal Security Service (FSB)."It's absolutely clear that in the area of counter-terrorism all relevant governments and international groups should work together."