Investors were anxious about the financial stability of Turkey, and how it might affect the global financial system.
The Dow and S&P 500 posted declines for the week following five straight weeks of gains, but the S&P 500 remains just 1.4 per cent below its record high from January 26.
At 2:47 p.m. (1847 GMT), the Dow Jones Industrial Average was down 270.25 points, or 1.06 percent, to 25,238.98, the S&P 500 had lost 25.21 points, or 0.88 percent, to 2,828.37 and the Nasdaq Composite had dropped 65.17 points, or 0.83 percent, to 7,826.61. The Dow Jones Small-Cap Growth TSM Index closed at 10,474.34 for a loss of -18.84 points or -0.18%.
Lam Research, Micron, Applied Materials and ON Semiconductor fell between 1 percent and 4.7 percent.
The TSX's energy group rose 0.22 points, or 0.11 per cent, while the financials sector slipped 1.81 points, or 0.59 per cent.
Microchip shares fell 9.9 percent, among the biggest decliners on the S&P, after disappointing second-quarter revenue forecast.
Judge orders government to turn around deportation plane
The woman, known in court papers as Carmen , is a plaintiff in a lawsuit filed this week by the American Civil Liberties Union . Carmen is a pseudonym for the woman who, along with her daughter, was seeking asylum because of domestic abuse in El Salvador.
The Turkish lira briefly dropped almost 20 percent against the dollar after US President Donald Trump tweeted that he has authorized the doubling of tariffs on steel and aluminum imports from Turkey. Tech stocks have been at the center of a sharp recovery in the S&P since a market rout in February, driving the index close to its record high.
"There is low volatility in the markets as the S&P and Nasdaq are just below all-time record highs, and it seems like markets are complacent right now", said Tom White, chief market strategist at TradeWise Advisors, in Chicago, Illinois.
Crude oil prices failed to make a decisive recovery on Thursday even though the USA sanctions against Iran went into effect on Thursday and the S&P 500 Energy Index closed the day 0.9% lower. "You have banks losing because the 10-year U.S. Treasury (yield) came down".
Declining issues outnumbered advancing ones on the NYSE by a 2.10-to-1 ratio; on Nasdaq, a 1.51-to-1 ratio favoured decliners.
Oil prices were down slightly as the escalating China-U.S. trade dispute cast doubt on the outlook for crude demand.