This is the first time the US has deployed regular troops in Somalia since 1994. However, some US counterterrorism experts are already stationed in the country.
In 1993, 18 US Special Forces soldiers perished in an incident immortalized in the Hollywood film 'Black Hawk Down.'
The deaths of the soldiers and the shooting down of two US helicopters in Mogadishu - the capital of Somalia - shocked the US, leading to the decision to withdraw its remaining troops from the country.
Hundreds of Somalis also perished in the 15-hour-battle sparked when US forces attempted to capture close allies of warlord Mohammed Farah Aideed.
Since then, the US has restricted most of its actions to drone and missile attacks against Islamist militants in Somalia.
According to BBC World Service Africa editor Mary Harper, the US has also trained a highly specialized elite Somali force.
Harper says that focus has now been turned to the Somali army, which is fractured, low on discipline and poorly equipped.
Al-Shabab has a strong presence In many rural areas of Somalia.
The terror group, part of al-Qaeda, often carries out attacks in Mogadishu and other parts of the country.
The African Union has approximately 22,000 soldiers assisting the Somali government fight al-Shabab.
Several other countries, including the United Kingdom and Turkey, are also training Somali soldiers.
Last month, United States President Donald Trump approved a directive allowing tougher action against the terror group.