time ago wrapping up a crucial call with ukraine's president where he told him the u.s. would respond, quote, swiftly and decisively to any further russian aggression. national security adviser jake sullivan warned again today that a russian invasion could come at any time. he made it clear there could be dramatic civilian casualties. >> if there is a military invasion of ukraine by russia it's likely to begin with a significant barrage of missiles and bomb attacks. those are never as precise as the army would -- any army would like them to be and we don't even know how precise the russian army would like them to be so innocent civilians could be killed regardless of their nationality. it would then be followed by an onslaught of a ground for moving across the ukrainian frontier. >> the u.s. state department is telling americans inside ukraine to leave the country and no rescues will come for anyone trapped there if russia invades. we're also seeing new radio