By Pavel Polityuk and Jeff Mason KYIV/WASHINGTON (Reuters) -The United States will hold Russia accountable for “war crimes”, the White House said on Monday, hours after Russia attacked Ukrainian cities with drones during morning rush hour, killing at least four people in an apartment building in Kyiv. Ukrainian President Volodymyr Zelenskiy, in his Monday evening video address, said there had been more attacks. “Right now, there is a new Russian drone attack. There are (drones) that have been shot down.” Interfax Ukraine news agency said Telegram users had reported blasts in the town of Fastiv…