Eritrean President Isaias Afewerki arrived in Addis Ababa on Sunday for a two-day official visit.
Ethiopian Prime Minister Abiy Ahmed and other senior government officials welcomed Afewerki upon arrival.
The presidential entourage includes Foreign Minister Osman Saleh and Yemane Gebreab, adviser to the president.
The two leaders are expected to discuss on ways of strengthening the efforts in fight against the COVID-19 pandemic and desert locust infestation, which have become a regional threat, the state-owned news agency ENA, said.
The Eritrean–Ethiopian diplomatic relations revived when premier Abiy in June 2018 extended an olive branch to his counterpart, ending two decades of tensions.
Between 1998 and 2000, the two countries fought a bloody war in which an estimated 70,000 people died.