U.S. stock index futures indicated slight gains for Friday's open after the Commerce Department released the first look at second-quarter economic growth.

Dow Jones Industrial Average futures pointed to a gain of about 15 points, while Nasdaq 100 and S&P 500 futures indicated gains of 0.2 percent and 0.4 percent, respectively.

The department said the U.S. economy grew by 4.1 percent in the second quarter, matching estimates.

That's the fastest rate of the growth since the third quarter of 2014 and the third-best growth rate since the Great Recession.

In recent days, White House officials have been indicating the reading will be strong. "You're going to get a very good economic growth number tomorrow. Big," White House economic advisor Larry Kudlow said ahead of the release.

"While we may be late in the game when it comes to our economic expansion, we're likely not in the last inning, and I think we see that in today's numbers," said Mike Loewengart, vice president of investment strategy at E-Trade. "Sure the trade war has begun to take its toll, but our economic fundamentals continue to be solid."