The State Department has ordered families of workers at the U.S. Embassy in Ukraine to leave the country beginning as soon as Monday, U.S. officials told Fox News.

The State Department will also begin telling American civilians in Ukraine next week to leave the country on commercial flights “while those are still available,” one U.S. official told Fox on Saturday. With Russian fighter jets currently stationed in Belarus, the country on Ukraine’s northern border, another official said the Pentagon is concerned Ukraine’s capital of Kyiv is “now in the crosshairs.”

The U.S. Embassy in Kyiv had already requested authorization to begin an evacuation of nonessential personnel as well as their families, CNN reported earlier on Saturday. When asked for comment, a State Department spokesperson told CNN the agency had “nothing to announce at this time.”

The reports come amid speculation over whether Russian president Vladimir Putin intends to invade Ukraine. Russia has stationed over 100,000 troops at the Ukrainian border in recent weeks, while Putin has demanded that Ukraine be barred from joining the North Atlantic Treaty Organization.

Meanwhile, the U.S. Embassy in Kyiv touted an American arms shipment that arrived in Ukraine on Friday.

“My guess is he will move in, he has to do something,” President Biden said of Putin at a press conference on Wednesday.

While Biden said “Russia will be held accountable if it invades,” he then added “It depends on what it does. It’s one thing if it’s a minor incursion and then we end up having a fight about what to do and not do, et cetera.”

The remark led Ukrainian president Volodymyr Zelensky to state on Twitter that there are “no minor incursions.”

“We want to remind the great powers that there are no minor incursions and small nations. Just as there are no minor casualties and little grief from the loss of loved ones,” Zelensky wrote. “I say this as the President of a great power.”