The US has added jihadist Al-Shabaab's deputy leader to its list of global terrorists.
Abukar Ali Adnan will now be subject to strict sanctions, the State Department said Thursday.
The Al-Qaeda-affiliated al-Shabaab militants have been fighting to overthrow the UN-backed Somali government since 2007.
Two other al-Qaeda leaders - Muhammad al-Ghazali (in Arabian Peninsula) and Wanas al-Faqih (in Islamic Maghreb) - were also added to terrorists' list.
"Al-Ghazali is involved in internal security and training of the group's operatives," the US State Department said.
"Wanas al-Faqih planned the March 18, 2015 Bardo museum attack in Tunisia that killed at least 20 people," it added.
The three will be blocked from accessing property or interests and engaging in any transactions with the US and its citizens.
The move coincides with the escalation of US military strikes on terrorist targets in Somalia.
According to a Washington think-tank, the US conducted 35 airstrikes in Somalia during Donald Trump's first year in office, a significant increase over prior years.
Former president Barack Obama's administration is said to have carried out a similar number of air strikes in Somalia in eight years.