The United States gave jeeps, communications technology and small aircraft to Tunisia on Thursday to help protect the border with Libya, where Islamic State (IS) group has gained ground and set up training camps, officials said.
The North African country was also expecting to receive a number of attack aircraft, Defense Minister Farhar Horchani said, though he did not give details on who would supply them.
Tunisia has already built a 200-km (120-mile) barrier along the frontier to guard against militants since gunmen trained in Libya targeted tourists in attacks on a beach hotel and a Tunis museum last year.
IS group also launched a major assault on the border town of Ben Guerdane in March.
US Assistant Secretary for Defense Amanda Dory said at a ceremony in Tunis that the jeeps, Maule light aircraft and a communication system between them would help Tunisian forces improve their monitoring of the border.
Horchani said the US package was worth around $20 million. The US ambassador said it consisted of 48 jeeps and 12 aircraft.
Western governments are giving Tunisia financial and military aid to support its young democracy, which they are holding up as a model for the region since its 2011 uprising ousted autocrat Zine El-Abidine Ben Ali.
A small group of Islamist militants tied to al Qaeda is fighting in remote mountains near the Algerian border. Other Tunisian militants have split to join IS in Libya.
On Wednesday, four police were killed when a militant detonated his bomb belt during a raid on a house in Tataouine in the south. That and a raid in Tunis were part of an operation that stopped planned attacks on the capital, authorities said.
More than 4,000 Tunisians are thought to have left to fight for IS group and other militant groups in Iraq and Syria. Some are returning to join the group in Libya, threatening more attacks on Tunisia.