New Delhi, The S&P 500 has entered correction territory, as investors reacted to Russian President Vladimir Putin's decision to order troops to breakaway regions of Ukraine, escalating tensions and raising fears of a full-scale invasion, Market Watch reported.

Markets in the US were closed Monday in observance of the Presidents Day holiday, with trade on Tuesday providing the first opportunity for investors to react to developments in Eastern Europe.

On Friday, the Dow, S&P 500 and Nasdaq Composite logged a second straight weekly decline. A so-called death cross crystallized in the Nasdaq, a bearish chart pattern, the report said.

The S&P 500's fall left it 10.3 per cent below its record close on January 3. A correction is commonly defined by market technicians as a fall of at least 10 per cent (but not greater than 20 per cent) from a recent peak.

S&P 500 logged its first correction in 2 years as the Russia-Ukraine conflict escalated.

Sentiment soured in the US stock market after Putin ordered forces Monday into separatist regions of eastern Ukraine, raising fears that an invasion was about to materialize, Market Watch reported.

"Military confrontations are scary," but the market seems to believe the confrontation over Ukraine will be "limited," said Jeffrey Kleintop, chief global investment strategist at Charles Schwab. "The market reaction is mild relative to a lot of the fears" over potential spillover effects, such as "fears of World War III" or a recession, he said.