The United States and the United Nations imposed sanctions Wednesday against Libyan militia leader Ibrahim Jadhran, whose forces attacked oil terminals in eastern Libya in June.
The measures block all of Jadhran's assets within US jurisdiction, and Americans are generally prohibited from engaging in transactions with him.
In addition, corresponding UN sanctions will "require all UN Member States to impose an asset freeze and travel ban," the US State Department said in a statement.
Armed groups led by Jadhran seized the Ras Lanuf and Al-Sidra oil export terminals on June 14, before they were recaptured by military strongman Khalifa Haftar's forces.
"This created an economic and political crisis that cost Libya more than $1.4 billion in revenue and set back efforts to promote political progress and stability in Libya," the State Department said.
"Libya's oil facilities, production and revenues belong to the Libyan people."