Story highlights Elizabeth Warren said she wants 'an honest conversation about our posture overseas'

Pentagon officials briefed members of the Senate armed services committee

(CNN) Sen. Elizabeth Warren says there are "more questions than answers" about what led to four US soldiers being killed in the October 4 Niger ambush, and she's arguing for Congress to have a bigger role in determining how US troops operate in countries like Niger where they don't have an active combat mission.

Warren, who sits on the Senate armed services committee, told CNN the attack was yet another sign that Congress is long overdue to debate a war authorization that better defines the US' counterterrorism role.

In her first public comments on the Niger ambush, the Massachusetts Democrat said it was time for "an honest conversation about our posture overseas."

"When we deploy soldiers to places like Niger that aren't considered active combat zones, what are there authorities and rules of engagement, what kind of force protection do they have, what level of risk are we as a country putting them at?" Warren said. "These are decisions that require congressional input."

Warren and the rest of the Senate armed services committee were briefed by Pentagon officials Thursday about the circumstances of the Niger attack and what investigators have determined so far.

Read More