The EU's top diplomat said Thursday that NATO offered the best security guarantee for Ukraine, accusing President Donald Trump of falling for a Russian narrative by closing the door.In an interview with AFP on a visit to Washington, Kaja Kallas also warned that the Europeans would not be able to assist in an eventual ceasefire deal in Ukraine's three-year conflict with Russia unless they are included by Trump, who has reached out directly to Russian President Vladimir Putin.Kallas, a former prime minister of frontline state Estonia, said NATO countries have never attacked Russia which instead was "afraid of democracy."