U.S. President Joe Biden did little to tip his hand about his unannounced visit to Kyiv, heading to church on Saturday afternoon and then taking his wife out to dinner at a cozy Washington restaurant.

But by the pre-dawn hours Sunday, he was already aboard a U.S. military plane crossing the Atlantic, the first leg of an itinerary to the Ukrainian capital carried out under cloak-and-dagger secrecy after months of meticulous planning by a close circle of advisers.

Americans woke up on a public holiday, Presidents¡¯ Day, to clips of Biden in his trademark aviator sunglasses strolling in the cold next to Ukrainian President Volodymyr Zelenskyy as air raid sirens blared in the background.