The Pentagon has confirmed that there are 6,000 US troops stationed throughout Africa.

The four US soldiers killed in Niger were on a counterterrorism mission against ISIS-affiliated militants.

The Chairman of the Joint Chiefs of Staff has committed to redoubling communication efforts between the Pentagon and Congress on military matters.

The Pentagon has announced that the US has over 6,000 soldiers stationed throughout Africa, even though several senators had previously been surprised to learn that there are even 1,000 American soldiers on the continent.

Gen. Joseph Dunford, the Chairman of the Joint Chiefs of Staff, said at a press conference Monday that the US has about 800 soldiers stationed in Niger alone, which is where four American troops were killed earlier this month by ISIS-affiliated militants.

The press conference comes after several US senators including Sen. Lindsey Graham, Sen. Chuck Schumer, and Sen. John McCain had all expressed surprise that the US had a large number of troops in Niger and 6,000 across all of Africa.

"I didn't know there was 1,000 troops in Niger," Graham said Sunday on NBC's "Meet the Press." "This is an endless war without boundaries and no limitation on time and geography ... You've got to tell us more."

Dunford described the US presence in Niger and other African countries as advisory and meant to help local allies defeat extremist militants, namely Al-Qaeda, ISIS, and the Nigerian Islamist group Boko Haram. He said the number of American troops currently in Niger is the largest amount present in any single African country.

Dunford acknowledged the lack of communication between military leaders and Congress, and said he and Secretary of Defense James Mattis would "double" their efforts to communicate better with senators.