WILMINGTON, Del. (AP) — White House national security adviser Jake Sullivan says Russia could invade Ukraine "any day," launching a conflict that would come at an "enormous human cost."

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The senior adviser to President Joe Biden offered the stark warning Sunday, the day after U.S. officials confirmed that Russia has assembled at least 70% of the military firepower it likely intends to have in place by mid-month to give President Vladimir Putin the option of launching a full-scale invasion.

Meanwhile, elite U.S troops and equipment landed in southeastern Poland near the border with Ukraine.

The troops are part of a deployment ordered by Biden to show the U.S. commitment to eastern flank NATO allies.

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