U.S. stock index futures pointed to a lower open Friday as China's trade data for July fell short of expectations. 

Futures on the Dow Jones Industrial Average were down 0.37 percent, those on the Standard & Poor's 500 index were down 0.44 percent, while futures on the Nasdaq 100 index were down 0.27 percent.

Market confidence was weighed down after China reported a trade surplus of $25.1 billion in July with slower-than-expected growth in exports and imports. The customs data released Friday show that the exports advanced just 1 percent in July compared to the same month last year,  and down from 11.3 percent in June. Imports rose 4.7 percent in July compared to the same month last year, down from 6.3 percent in June.

The Labor Dept. will report the import price index Friday, which measures the change in the price of imported goods and services purchased domestically. The index is expected to rise 0.1 percent in July, up from a 2.7 percent decline in June.

The Department of the Treasury will issue a report Friday the Federal budget, which measures the difference in the value between the federal government's income and expenditures. The federal budget deficit in July is expected to have grown to $103 billion, up from $60 billion in June.

On Thursday, U.S. stocks were mixed as investors remained cautious after a decline in the number of initial jobless claims was reported. The initial jobless claims report showe that such claims dropped to 361,000 for the week ending Aug. 4, down from 365,000 the previous week. The trade deficit was reported to be $42.9 billion in June, down from $48 billion in May.

The Dow Jones Industrial Average fell 0.08 percent, the S&P 500 Index was up 0.04 percent and the Nasdaq Composite Index advanced 0.25 percent.

Major European indices were in the red as investors were concerned about China's economic condition after disappointing trade data was reported for July. London's FTSE 100 was down 12.56 points, Germany's DAX 30 Index fell 34.99 points and France's CAC 40 dropped 14.97 points.

Asian stocks were also down on the market's concern that the ongoing debt crisis in Europe and the tentative U.S. recovery are hurting the demand for exports from China.