Chad and Israel have renewed diplomatic ties in what Israeli Prime Minister Benjamin Netanyahu has described as "a partnership... to forge a prosperous and secure future for our countries".
His comments came during a brief visit to Chad where he was welcomed by President Idriss Deby.
In recent years, Israel has made a big effort to improve diplomatic relations with several African countries.
Chad, which has a majority Muslim population, cut ties in 1972.
Mr Netanyahu's visit reciprocates President Deby's trip to Israel last November, the first by a Chadian leader.
In addition to renewing diplomatic ties the two leaders signed several agreements, Mr Deby told a joint press conference, but did not say what those deals were.
"The purpose of your visit is to bring our two countries closer and to cooperate," he told Mr Neytanyahu, the Haaretz newspaper reports.
Chad is interested in "security, intelligence, technology and a pathway to Washington", writes Jerusalem Post diplomatic correspondent Herb Keinon.
For his part, the Israeli prime minister is trying to separate the peace process with the Palestinians from relations with majority-Muslim countries, Mr Keinon adds.
In 2016, Mr Netanyahu became the first Israeli premier to visit Africa in nearly three decades, with a trip to Uganda, Ethiopia, Kenya and Rwanda.
A year later he attended a meeting in Liberia of heads of state from the West African regional group, Ecowas. But an Israel-Africa summit that was supposed to take place in Togo in October 2017 was cancelled.