A top White House aide on Sunday asserted that Russia could invade Ukraine “any day” now amid a weeks-long standoff between Moscow and Washington. “It could happen as soon as tomorrow or it could take some weeks yet,” Biden administration National Security Adviser Jake Sullivan told ABC News on Sunday. Russian President Vladimir Putin, he added, “has put himself in a position with military deployments to be able to act aggressively against Ukraine at any time now.” “We believe that there is a very distinct possibility that Vladimir Putin will order an attack on Ukraine. It could take a number of different forms. It could happen as soon as tomorrow or it could take some weeks yet,” Sullivan said, stressing the United States is still trying to pursue a path of diplomacy. Russia has amassed a significant number of troops along the Russia-Ukraine border in recent weeks. Troops have also been …