Al-Shabaab “remains a threat, and in fact the threat is increasing,” Defense Department spokesman John Kirby told reporters Monday. The U.S. has been sending forces into the country when needed, Kirby said, but “the advise-and-assist mission works best” when “you’re on-site” and can work continually with local fighters.

Earlier: U.S. Forces to Begin Withdrawing From Somalia on Trump’s Orders

White House Press Secretary Karine Jean-Pierre said the “small but persistent presence” was deemed necessary “to maximize the safety and effectiveness of our force.”

The moves breathes new life into a two-decade-long global fight against terrorist groups that began following the Sept. 11, 2011 attacks. Biden campaigned for president on a promise to wind down what he called the US’s “forever wars” and last year pulled out forces from Afghanistan in a chaotic withdrawal that damaged his political standing.

The US had about 700 troops in Somalia before Trump ordered them out of the country in an effort to make good on his own pledge to bring soldiers home. US Africa Command relocated them to an undisclosed location in East Africa, from which they periodically re-entered Somalia to train and advise local forces fighting al-Shabaab.

The pull-out, which happened against the recommendation of military leaders at the very end of the Trump administration, put US forces in greater danger by having them travel in and out of the country and disrupted their efforts to build the capacity of Somali anti-terror fighters, according to one senior administration official.

The troops will continue their training and advisory roles as well as help to turn intelligence into counterterrorism operations and help prepare for offensive missions to dislodge al-Shabaab from their positions, the official said.

The Special Operations forces also will be responsible for helping limit al-Shabaab’s ability to execute complex operations by targeting its leadership, another official said.

The decision to send US troops back to Somalia was in part motivated by what the Biden administration sees as a growing threat posed by al-Shabaab. A senior administration official said the group is the largest and best financed al-Qaeda affiliate. Its forces have killed more than a dozen Americans in East Africa, including three in a January 2020 attack on a military base in Kenya.

–With assistance from Roxana Tiron and Jordan Fabian.