CIA Director John Ratcliffe’s surprise trip to Moscow this week was intended to warn Russia against attacking NATO countries -- particularly Estonia, Latvia, and Lithuania -- sources familiar with the visit have told RFE/RL.Ratcliffe's August 25 trip, his first publicly known visit to Russia since becoming CIA director under President Donald Trump, comes amid growing concern in the Baltic states over Russian aggression.A Baltic diplomat who spoke to RFE/RL on condition of anonymity said officials “were pre-warned” about Ratcliffe’s visit to Moscow.Russia has confirmed the visit, with Sergei Naryshkin, director of Russia's Foreign Intelligence Service, saying that he held a “working-level meeting” with the CIA director. He gave no further details, only saying that they discussed unspecified sensitive matters.Baltic FearsLeaders in Estonia, Latvia, and Lithuania -- all of whom are NATO members -- have long warned about Russian aggression.RFE/RL reported on August 26 about a letter addressed to European Commission President Ursula von der Leyen and signed by the three Baltic commissioners -- Kaja Kallas, Andrius Kubilius, and Valdis Dombrovskis -- that warned of the "deteriorating security environment" in the Baltics and increased Russian "airspace violations and drone incursions."