U.S. index futures fell in Asian trade, S&P 500 -0.5% to 6,621.5, Nasdaq 100 -0.6% to 24,225, Dow -0.3% to 46,771.
Investors watch Trump's deadline for Iran to reopen the Strait of Hormuz, threatening U.S. strikes if missed by 8 p.m. ET Tuesday.
The Strait of Hormuz handles about 20% of global oil flows; disruption has pushed crude prices higher, adding to inflation concerns.
ISM PMI fell to 54.0 in March, missing 54.8 forecast, while the prices‑paid index posted its biggest 13‑year rise, signaling inflation pressure.