* ADP employment report comes in below expectations
* U.S. defense secretary says North Korea a danger
* Indexes down: Dow 0.6 pct, S&P 0.9 pct, Nasdaq 1 pct
By Caroline Valetkevitch
NEW YORK, April 3 (Reuters) - U.S. stocks fell on Wednesday as weaker-than-expected economic data caused investors to trim positions ahead of Friday's jobs report and U.S. defense secretary expressed concern over North Korea.
A report on private-sector jobs showed less-than-expected hiring in March, which some analysts saw as a discouraging sign ahead of Friday's Department of Labor report.
Stocks extended losses in afternoon trading, with the S&P 500 and Nasdaq falling more than 1 percent. The Pentagon said it was sending a missile defense system to Guam in the coming weeks, while U.S. Defense Secretary Chuck Hagel cited a "real and clear" danger from North Korea.
The drop put the S&P 500 on track for its biggest daily percentage loss since Feb. 25, with energy and financial sectors leading the decline. The S&P 500 financial index was down 1.7 percent.
The S&P 500, up roughly 10 percent since the start of the year, has come close to its intraday record level of 1,576.09 in the past few sessions before pulling back, and analysts said the market is facing bearish technicals after its strong run.
"It's not really a surprise given how extended the market is that with some weaker economic data you're seeing some risk-off action going on today. People are paring positions across the board," said Michael James, managing director of equity trading at Wedbush Securities in Los Angeles.
The headlines on North Korea add "another risk element to the market," he said.
The Dow Jones industrial average was down 84.50 points, or 0.58 percent, at 14,577.51. The Standard & Poor's 500 Index was down 14.13 points, or 0.90 percent, at 1,556.12, after briefly falling more than 1 percent. The Nasdaq Composite Index was down 32.79 points, or 1.01 percent, at 3,222.07.
On Tuesday, decliners had beaten advancers in the market despite gains in the three major indexes.
The ADP National Employment Report showed U.S. companies hired at the slowest pace in five months, far below what economists had expected, though the February report was revised upward.
In another report, the Institute for Supply Management's March services sector index also came in below expectations, with the pace of growth at the lowest level in seven months.