WATCH: Peter Doocy grills Psaki on US drone strike that killed 10 civilians including seven children

"You said last month our over-the-horizon capacity can work and has worked in going after ISIS targets, including people who went after our troops," Doocy said.

"But, you guys didn't kill people who went after our troops; you killed ten civilians, including seven children. So, does the president still think that these over-the-horizon strikes can work?" Doocy questioned Psaki.

"Absolutely," replied Psaki at the White House press conference Monday. "And, I will just reiterate, as our Secretary of Defense conveyed, as General McKenzie conveyed, that there was a serious mistake."

"The Secretary of Defense has authorized—as I noted before—a thorough review of the investigation just completed by US Central Command, including the degree to which the investigation considered all available contexts and information, the degree to which accountability measures need to be taken, at which level, and the degree to which strike authorities, procedures and process need to be altered in the future. That's an important process," Psaki continued.

Psaki then went on to split hairs between an over-the-horizon drone strike and a "self-defense" strike. "I would note, which I noted earlier, that there's a difference between a self-defense strike, which is exactly what this was—and I would note there was one prior to this that was a successful self-defense strike—and those that [are] posing an imminent threat to US forces, who were, as we know, on the ground at that time, facing threats in real time, and an over the horizon strike, where we typically expect to have more time to assess both the threat and the potential target," Psaki said at the press conference.

"That is a different approach, and requires a different approach, and it's a different approach internally," Psaki concluded.