President Joe Biden called off a second retaliatory strike against Iran-backed militias in Syria last week after being told that civilians were at risk, according to officials quoted in US media.
The US military said it targeted infrastructure belonging to Iranian-backed Iraqi militia groups Kataib Hezbollah and Kataib Sayyid Al Shuhada during strikes near the town of Bukamal, on the Syria-Iraq border, on February 25.
Mr Biden called off an air strike against a second target in Syria after civilians were spotted in the area, US broadcaster NBC reported, quoting a senior administration official.
The president made the decision when military reconnaissance revealed a woman and two children in the courtyard of the intended target, according to the official.
The order to call off the second strike, which was also reported by the Wall Street Journal, came as military aircraft were about to bomb the target.
The US strike came after a rocket attack on a military complex in Erbil, where US-led coalition troops are based, on February 15. The strike in the semi-autonomous Kurdistan Region of Iraq killed a civilian contractor and wounded a US serviceman and nine others.
The US said its response was proportionate and "conducted together with diplomatic measures", including consultation with US partners in the anti-ISIS coalition.
The Biden administration sent a private message to Iran after the strike, the official told NBC.