President Trump has privately told aides that he would consider ending the ceasefire with Iran if Tehran kills American troops, U.S. officials said.
The president's reluctance to reignite the war suggests he might be willing to withstand smaller flare-ups for weeks—or even months—to avoid a broader conflict in the Middle East.
The U.S. and Iran have engaged in intense fighting since a ceasefire went into effect in early April, with Iran firing missiles and drones on regional U.S. bases and Kuwait's international airport.
Secretary of State Marco Rubio described the tit-for-tat attacks as purely defensive in nature and not a renewed outbreak of full-scale war.
However, U.S. officials said the repeated attacks have ratcheted up pressure on Trump and cast doubt over the long-term viability of the ceasefire.