US stocks declined on Monday as fading hopes of a Middle East breakthrough and rising inflation concerns weighed on sentiment. The Nasdaq 100 Index fell 0.8% at 9:55 a.m. in New York, putting the technology-heavy gauge on track to give back gains made over the previous two sessions. Notable decliners included ARM Holdings Plc, Sandisk Corp. and Datadog Inc. The S&P 500 Index declined 0.5%.

Iran and the US seemed far apart on a new ceasefire deal as well as reopening the Strait of Hormuz, with Tehran saying it's sticking to a proposal rejected by US President Donald Trump. The stalemate has pushed Brent crude to about $107 a barrel even as Saudi Arabia's key oil pipeline started exporting oil again. At the same time, a selloff in US Treasuries resumed.

"As much as the Administration will likely spend a lot of time highlighting the existing of worthwhile 'talks' between now and the midterm election, it does not look like anything significant will take place," said Miller Tabak's Matt Maley. "As long as Iran insists on having control of the Strait of Hormuz, any dip in oil prices will likely be quite short-lived."

The week is filled with key economic reports expected to add evidence that the US economy is strengthening, bolstering the case made by several Federal Reserve officials that interest rates should be higher. Tuesday will bring consumer confidence data for September and August JOLTS data. Investors will also focus on the artificial intelligence trade, with Micron Technology Inc. scheduled to report results on Wednesday. Among single-stock moves, Nvidia Corp. gained after boosting its share buyback plan by a record $150 billion.