Analysts believe Iranian-backed groups are behind the attacks.
On Wednesday alone, there were three missile and drone attacks in Iraq and Syria, targeting US military and diplomatic personnel.
In particular, at least 14 missiles were fired at the Iraqi airbase, where US forces are stationed, as a result of which two American soldiers were injured.
While no one has claimed responsibility for the attacks so far, analysts believe Iranian-backed armed groups were behind them.
“They are using deadly weapons. I don’t know if it can be called anything other than a serious threat, “Pentagon spokesman John Kirby told reporters.
Tehran denies supporting attacks on US troops in Iraq and Syria and condemns US airstrikes against pro-Iranian groups.