Why a Russian invasion of Ukraine appears imminent despite intense diplomatic efforts

The Biden administration on Friday issued its most urgent warning yet that Russia could launch a war in Ukraine at any time. More than 100,000 Russian troops surround Ukraine on three sides, and national security adviser Jake Sullivan urged Americans to leave by the end of the weekend. U.S. officials tell our Nick Schifrin, they fear the war could start next week. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders