US stock index futures have dipped today as dour forecasts from Applied Materials and Nvidia weigh on shares of chipmakers and a recovery in Turkey's lira runs out of steam.

Shares of Nvidia have dropped 4% in pre-market trading after the chipmaker said cryptocurrency-fuelled demand had dried up and forecast current-quarter sales below Wall Street estimates.

Applied Materials slid 5.2% after the world's largest supplier of chip equipment forecast current-quarter results below estimates, adding to fears that a two-year chip boom may be losing steam.

Micron fell 1.3%, while Intel slipped 0.4%. Dutch chip equipment maker ASML's US-listed shares dropped 1.1%.

The lira weakened roughly 6% against the dollar after a US warning that Ankara should expect more sanctions unless it hands over detained American evangelical pastor, Andrew Brunson.

The fresh salvo at Turkey dulled yesterday's market optimism,which was due to waning trade worries after the United States and China said they would hold fresh talks later this month.

Just before lunchtime Irish time, Dow e-minis were down 26 points, or 0.10%.

S&P 500 e-minis were down 3 points, or 0.11% and Nasdaq 100 e-minis were down 10.75 points, or 0.15%.

Second-quarter earnings have been stronger than expected,with 79.3% of the 463 S&P 500 that have reported so far beating analyst expectations, according to Thomson Reuters.

Meanwhile, European shares are steady as investors are cautious about the Turkish lira's recovery as well as the latest efforts by China and the United States' to avert a trade war.

In London the FTSE is 0.49% lower at 7,518, while all of the major euro zone markets are little changed.

The CAC in Paris has fallen 0.44% to 5,325 and in Frankfurt the DAX is down 0.73% at 12,147

In Dublin the ISEQ has risen 0.03% to 6,674. AIB and Bank of Ireland are among the best performers while Kenmare and Cairn Homes have both lost value so far today.

Earlier in Asia, Hong Kong stocks ended with gains after five straight days of losses, tracking rebounds by Wall Street and European markets over news of fresh US-China trade talks.

The Hang Seng Index added 0.42% to close at 27,213.

But the benchmark Shanghai Composite Index continued its week-long losing streak, shedding 1.34% to close at 2,668.

And the Shenzhen Composite Index, which tracks stocks on China's second exchange, dropped 1.69% to end at 1,442.

Meanwhile, in Tokyo the key Nikkei added 0.35% to close at 22,270, while the broader Topix index firmed 0.62% to 1,697.