(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.
Warren joined the Senate armed services committee this year, one of several moves she has made that's generated buzz about a possible presidential run in 2020. The powerful committee is often a springboard for presidential candidates to build a national security resume.
In the interview, Warren took a swipe at President Donald Trump for his comments on Thursday that he did not authorize the US mission in Niger that led to the ambush.
"If that's true, it's extremely worrisome," she said. "The President is the commander in chief, he is responsible for every US military action that occurs while he is in office."
White House spokesman Raj Shah said in response to questions about Trump's statement that "the President has empowered military leaders to train and assist partner governments as we defeat ISIS and other terrorist groups in the region."
Warren said Thursday that she still has questions about the circumstances of the Niger ambush itself, echoing her colleagues who said the Pentagon was being more forthcoming to Congress but still did not have the full picture of the ambush.
"We need to understand what happened in the hour between when the attack happened and when additional assets arrived at the scene, and why we couldn't find one of our service members for 48 hours," Warren said. "We also need to understand if there are failures of intelligence both in terms of this specific operation and in terms of our broader ability to understand what's happening on the ground in this part of the world."
She argued that the questions being asked in the aftermath of the Niger ambush have already been lingering because the Trump administration has yet to define its counterterrorism strategy and Congress has failed to pass a new war authorization.
"We have troops deployed all around the world in support of counterterrorism missions. The Pentagon needs to do a better job of keeping Congress informed, and we in Congress need to do a better job of fulfilling our oversight responsibilities," she said.