On Friday, US media reported that the US was investigating the reason why its air defense system was not fully operational during a strike on its base in Syria.
"We've seen no indication that they had ... that kind of knowledge. And in the past, on some of these other attacks, I mean, they have used similar capabilities to go after our troops and our facilities there in Syria. So there's no indication that they would have had knowledge of that," Kirby told the US broadcaster.
On Thursday, a drone of presumably Iranian origin attacked a maintenance facility at the base in Syria's Al-Hasakah province, killing a US contractor and injuring six others, according to the US Department of Defense.
On Friday, in response to the drone attack, the US military carried out airstrikes on facilities belonging to groups affiliated with Iran's Islamic Revolutionary Guards Corps (IRGC), US Defense Secretary Lloyd Austin said.
The US military controls parts of the provinces of Al-Hasakah, Raqqa, Aleppo and Deir Ez-Zor, where the largest Syrian oil and gas fields are located. The Syrian government has repeatedly called the US military presence in the provinces an occupation aimed at stealing Syria's oil.