DR Congolese President Félix Tshisekedi arrived in Angola Tuesday following an invitation by President João Lourenço.
The visit is President Tshisekedi's first abroad after his inauguration last month.
The Congolese leader was due to have a private meeting with his Angolan counterpart, before leaving for Kenya and later Congo Brazzaville.
One issue presidents Tshisekedi and Lourenço were likely to discuss is the Congolese migrants in Angola.
An estimated over 35,000 people fleeing from the central DRC's Kasai Province have reportedly been living in Angola since 2017.
The Congolese arrived mainly in Dundo, the capital of the north-eastern Luanda Norte Province.
Luanda Norte Province, located 656km north of the capital Luanda, shares borders with both DRC and Congo-Brazzaville.
DRC’s central region of Kasai experienced a spike in violence in September 2017, leaving at least 400 dead in an uprising that erupted when government forces killed a tribal chief and militia leader, Kamwina Nsapu, who had rebelled against former President Joseph Kabila.
The Kasai violence added to the DR Congo's woes, whose eastern side has been wracked by conflict since 1994, when Hutu militias fled across the border from Rwanda after carrying out a genocide against Tutsis and moderate Hutus.
Last year, lobby group Human Rights Watch (HRW) expressed its concern after Angola's mass expulsion of DRC migrants.
According to HRW, over 400,000 people were forcibly returned or fled Angola following an operation targeting illegal diamond mining in the northern Lunda Norte Province.
Italian President Sergio Mattarella was also expected to arrive in Angola later on Tuesday for a three-day visit.
The Italian leader is expected to address the Angolan parliament.
“This visit means a sign of a clear friendship between the two countries”, state-owned news agency Angop quoted Mr Florêncio de Almeida, the Angolan ambassador to Italy.