The US decisions in Africa could send a message to groups destroying northern Nigeria, like Boko Haram, that the US is not committed in the long term.
The mission has received little attention in the United States, but is considered a cornerstone of the Pentagon's global efforts to combat al Qaeda.
The document, which was sent to companies operating in the park and was seen by Reuters, cited an immigration circular that came into effect on Nov. 18.
Islamist insurgent group al Shabaab said it was behind the assault on the Elite Hotel in Lido beach, and that its gunmen battled security forces who rushed to the scene.
With the changes in the geopolitical context of the region, knitting together Israel, the UAE, Greece, Cyprus and Egypt in a network of shared interests, Somaliland could be an important region.
Somalia has been embroiled in deadly violence since 1991, when clan warlords overthrew leader Siad Barre and then turned on each other.
"We work hard to prevent civilians from getting hurt or killed during these operations designed to bring increased security and stability to Somalia."
The blast shook the ground, said Mohammed Ali, a shopkeeper in the area. At the city's Madina hospital, a nurse, Halima Nur, said it had received five people injured in the blast for treatment.