Democratic senator presses Pompeo on US forces in Niger

CNN has obtained a copy of the letter Menendez sent Tuesday to Pompeo inquiring about US policy and objectives in Niger as President Donald Trump's top diplomat prepares to brief the entire committee on the issue this week.

"The State Department has responsibility for formulating and executing US foreign policy. Congress has a responsibility to ensure that military operations that put our men and women in uniform in harm's way support our diplomatic effort," the letter said.

"I hope you will be able to provide the Committee with a full understanding of our efforts in Niger, including the authorities under which US personnel are are operating," it said.

Specifically, Menendez wants Pompeo to answer the following questions:

"AFRICOM has stated that the soldiers who were killed in Niger in October were operating under Title 10 Authorities. Under which specific chapter and section of Title 10 were they operating? In what other countries do these legal authorities provide the basis for missions by the US military?" "What military actions, if any, does the Executive Branch believe are, and are not, permitted under existing train, equip, and advise and accompany authorities? In what other countries do these legal authorities provide the basis for missions by the US military?" "Was our Ambassador in Niger made aware that an inaccurate concept of operations for the mission was sent up the military chain of command? What procedures are in place to ensure Chiefs of Mission have adequate information about what has been approve by the military chain of command and at what level the approval was granted?" "Is there a procedure in place through which our Chiefs of Mission can be sure that our country partners are in fact in the lead in missions; are fully briefed in advance of operations; and are being accompanied by US soldiers rather than led by US soldiers?" "Is there a whole-of-government strategy for Niger that includes adequate emphasis on diplomacy and development? What are our main diplomatic and development goals in Niger and how do they dovetail with the deployment of US troops?" "How long are US Armed Forces to remain deployed in Niger, and what diplomatic and development achievements are hoped to be achieved by the end of deployment?"

Menendez's letter comes on the heels of a Pentagon report was released earlier this month that determined a series of failures and deficiencies, including a lack of adequate training, contributed to the October ambush.

The Americans killed in the attack were Staff Sgt. Bryan C. Black, Staff Sgt. Jeremiah W. Johnson, Staff Sgt. Dustin M. Wright and Sgt. La David T. Johnson. Niger has not released the names of its soldiers who were killed in the attack.

"The investigation identifies individual, organizational, and institutional failures and deficiencies that contributed to the tragic events of 4 October 2017," a summary of a months-long military investigation into the incident said.

The United States has previously acknowledged it has troops there. But it's never gone into much detail.

In 2013, the White House announced that President Barack Obama had deployed 100 military personnel to Niger.

Since then, the number of US troops in the nation has risen to about 800.

Small groups of US special operations forces advise local troops as they battle Boko Haram and al Qaeda.