U.S. stock index futures were higher Tuesday even as the Middle East conflict kept oil prices pinned near $100 a barrel, putting inflation risks back in focus ahead of the Federal Reserve's two-day meeting starting later in the day.

Wall Street was also cooling from a tech-driven rebound in the previous session that saw the benchmark S&P 500 log its biggest one-day jump in over a month.

Nvidia's annual developer conferencewas also extensively watched. Nvidia said the revenue opportunity for its artificial intelligence chips may reach at least $1 trillion through 2027, as it outlined a strategy to compete more aggressively in the fast-growing market for running AI systems in real time.

Shares of the company were slightly up in premarket trading after Monday's 1.6% rise, while peers Advanced Micro Devices and Broadcom were marginally lower.

Investors were also focused on the expanding conflict in the Middle East that is likely to keep the Strait of Hormuz shut, as U.S. President Donald Trump's call to allies to safeguard the passage went unanswered.

Oil price-sensitive airlines that have faced the brunt of the selloff since the war started got some reprieve after Delta raised its revenue guidance for the current quarter on accelerated demand. The carrier's shares gained 3.6% and American added 1.2%.

On the flipside, cruise operators Carnival and Royal Caribbean were down 1%.

Brokerages lifted their outlooks for energy prices that are likely to dampen economic growth, a factor that the Australian central bank also flagged when it hiked interest rates earlier in the day.

The U.S. Fed is likely to leave borrowing costs unchanged at the end of its two-day meeting on Wednesday.

But investors are pricing in a hawkish outlook as short-term Treasury yields edge up and rate futures suggest just one 25-basis-point cut towards the end of the year, according to LSEG-compiled data, down from around two before the war.

"While we do not expect central banks to make knee-jerk policy moves, policymakers are likely to stress vigilance over inflation risks amid elevated oil prices and uncertainty over the length of the war," said analysts at UBS on central bank decisions globally this week.

"Comments that are more hawkish than expected could inject further volatility into a market that is vulnerable to shifts in sentiment."

At 8:38 a.m. EST, U.S. S&P 500 E-minis were up 10 points, or 0.15%, Nasdaq 100 E-minis were up 16.75 points, or 0.07%, and Dow E-minis were up 99 points, or 0.21%

Futures tracking the rate-sensitive Russell 2000 index lost 0.5%, while Wall Street's fear gauge, the CBOE volatility index, edged up 0.22 points to 23.73.

Despite the global turmoil in markets due to the war, U.S. stocks have held up better than those in Europe and Asia on expectations that the repercussions on the economy will be less severe.

However, analysts have underscored that investors are yet to fully consider the effects of the war on the global economy.

Honeywell International slipped 3.4% after the industrial giant said the conflict could hit its first-quarter revenue by a high-single-digit percentage, weeks after oilfield services company SLB flagged an earnings squeeze.

The conflict has also delayed a planned summit between U.S. and China's leaders on President Trump's request.

Among others, ride-hailing app Uber added 2.6% after announcing plans to roll out robotaxis in 28 cities starting next year, powered by Nvidia's autonomous driving software.

Energy companies Occidental, ConocoPhillips and EQT rose more than 1% each on higher crude and gas prices.