U.S. stock index futures slipped Thursday following gains in the previous session, as investors remained cautious about developments in the Middle East while weighing the prospects for de-escalation in the conflict.

U.S. President Donald Trump said Iran was desperate to make a deal to end the fighting, contradicting the Iranian foreign minister, who said Tehran was reviewing a U.S. proposal but had no intention of holding talks to wind down the war.

Contradictory signals from both sides left markets on edge, as hopes for a breakthrough to restore shipping through the crucial Strait of Hormuz remained uncertain.

"The relative calm in markets suggests some investor confidence that hostilities may eventually wind down, however slim that prospect remains," said Molly Schwartz, cross-asset macro strategist at Rabobank.

At 7L53 a.m. EST, Dow E-minis were down 356 points, or 0.76%, S&P 500 E-minis were down 54.50 points, or 0.82%, and Nasdaq 100 E-minis were down 237.75 points, or 0.98%.

Wall Street's main indexes closed higher on Wednesday after Washington delivered a proposal to Iran through Pakistan, while comments from Iranian officials suggested Tehran might be open to diplomatic offers even as it publicly denied any ongoing negotiations.

"Markets appear to have reached an impasse, with investors caught between two competing narratives ... this has created a fragile equilibrium across asset classes, where positioning reflects caution rather than conviction," said Daniela Hathorn, senior market analyst at Capital.com.

The escalating conflict in the Middle East has knocked the global economy off a stronger growth path, the OECD warned on Thursday, with a closure of the Strait of Hormuz threatening to push inflation sharply higher.

Central banks have been put in a tough spot with regard to interest rates, with money market participants no longer pricing in any easing from the U.S. Federal Reserve this year. Two rate cuts had been expected before the Iran conflict erupted, according to the CME Group's FedWatch Tool.

On the data front, investors will parse through weekly jobless claims data and comments from Federal Reserve officials Lisa Cook, Stephen Miran, Michael Barr and Philip Jefferson.

Among individual movers, Jefferies Financial was down marginally in premarket trading, as the investment bank missed analysts' estimates for first-quarter profit due to losses on loans to collapsed companies.

Shares of Olaplex Holdings jumped 50% after Germany's Henkel agreed to buy the hair-care brand in a $1.4 billion deal.

U.S.-listed shares of gold miners slipped as bullion prices declined more than 1%. Newmont slipped 3.1%, Sibanye Stillwater lost 4.4% and Harmony Gold shed 4%.