The Economic Community of West African States (ECOWAS) announced on Monday that it is closing Mali's land borders in an attempt to force out the junta that seized power 13 days ago.
The landlocked country imports nearly all its petroleum products from neighbouring Ivory Coast.
Mali's account at the regional central bank has also been frozen, meaning the junta will struggle to pay public-sector staff.
"All of the measures are applicable until the constitutional order is restored," said Ivory Coast President and ECOWAS chairman Alassane Ouattara.
The junta, which calls itself National Committee for the Redressment of Democracy and Restoration of the State, insists that its priority is "to recover the country's territorial integrity which is threatened by the crisis in the north."
Tuareg fighters bristling with arms from war-torn Libya and Islamist militants with links to Al-Qaida in the Islamic Maghreb have taken power there after trouncing government forces.