U.S. stock indexes were set for a weaker open on Friday, a day after staging a dramatic late rally, as developments around a raging war in Ukraine kept investors on edge.

After Russian troops invaded Ukraine, the U.S. government, the European Union and several other countries imposed sanctions against Russia aimed at limiting its ability to do business in major currencies.

The coordinated response helped dampen risk sentiment in the previous session, causing Wall Street to rise sharply, leading the Nasdaq up 3 percent after a weak opening.

"It is too early to assume that the sanctions will force Russia to back down, or that any other nation will not get involved," said Charalambos Pissouros, head of research at JFD Group.

"Thus, we prefer to treat yesterday's recovery in risk assets as a corrective rebound and we see decent chances for another leg south."

Morgan Stanley and Microsoft Corp fell around 1% each in premarket trading to lead losses among big banks and megacap growth names.

Oil majors Exxon Mobil and Chevron Corp slipped about 0.7%, tracking crude prices.

Defense stocks Lockheed Martin Corp, Northrop Grumman Corp and L3Harris Technologies Inc all rose more than 1%.

At 06:19 a.m. ET, Dow e-minis were down 286 points, or 0.86%, S&P 500 e-minis were down 38 points, or 0.89%, and Nasdaq 100 e-minis were down 113.25 points, or 0.81%.

Key indices posted their third straight weekly decline as geopolitical tensions dealt a severe blow to investors already worried about the Federal Reserve's aggressive plans to tighten policy.