The US notified high-ranking Ukrainian officials in advance. They also informed other allies but it is not clear if these embassies will follow suit," Jennifer Jacobs (a senior White House reporter at Bloomberg News) tweeted Tuesday.

Reuters reports that columns of tanks and military vehicles were seen near Donetsk on Tuesday morning.

According to Reuters, there were "roughly five tanks in a column at the edge of the city" and "two more in another area of town, but no insignia were apparent."

NBC News reports that Russian troops are moving closer to the border, in what appears to be plans to invade at any time.

This is after Jonathan Finer, White House Principal Deputy National security Adviser, stated that US President Joe Biden had warned that he would take all necessary steps to ensure the safety of diplomatic staff.

Finer said that all signs on the ground indicate a step towards military action and not diplomacy.

Closed-door meetings of the United Nations Security Council seem to be in progress, and updates will be closely monitored.

Reaction of the market

Markets remain nervous as risk-recovery efforts are abandoned in the face of West-Russia tensions. S&P 500 futures are down 0.35% per day, while gold prices remain below new eight-month highs at $1,914.