WASHINGTON (REUTERS) - United States stock indexes opened higher for the first time in four days on Friday (Aug 11) after tepid data pointed to benign inflation that could make the Federal Reserve cautious about raising rates again this year, even as concerns lingered over rising tensions between the US and North Korea.

Still, the S&P 500 is on track to post its biggest weekly loss in about nine months. In his latest warning to North Korea, US President Donald Trump said on Friday (Aug 11) military solutions were "fully in place"and referred to American weapons as being "locked and loaded" should the nuclear-armed nation act "unwisely".

The tensions, since Mr Trump's "fire and fury" comments on Tuesday (Aug 8), have wiped out nearly US$1 trillion (S$1.36 trillion) from the global equity markets. "The escalation of the geopolitical situation between the US and North Korea is beginning to rattle investors' nerves, as was witnessed in the VIX index yesterday," said Peter Cardillo, chief market economist at First Standard Financial.

"The overall 'fear factor' is the markets worst enemy that will feed on itself, leading to increased hedging."

On Thursday (Aug 10), the CBOE Volatility Index, a barometer of expected near-term stock market volatility, closed at its highest since the US presidential election.

The Labor Department said on Friday its Consumer Price Index edged up 0.1 per cent in July. The data comes amid tepid inflation that has remained below the Fed's 2 per cent target, despite low unemployment.

At 9.34am ET (9.34pm Singapore time), the Dow Jones Industrial Average was up 54.06 points, or 0.25 per cent, at 21,898.07; the S&P 500 was up 5.23 points, or 0.21 per cent, at 2,443.44. The Nasdaq Composite was up 19.35 points, or 0.31 per cent, at 6,236.22. Seven of the 11 major S&P 500 sectors were higher, with the technology's 0.36 per cent rise leading the advancers. Declining issues outnumbered advancers on the NYSE by 1,339 to 865. On the Nasdaq, 1,378 issues rose and 892 fell.