Somalia accused Kenya of violating its sovereignty after a representative of the breakaway region of Somaliland was invited on Tuesday to a diplomatic briefing in Nairobi.
Mogadishu's ambassador to Nairobi, Mohamoud Ahmed Nur, walked out of the event in protest at the presence of the Somaliland envoy, its embassy said in a statement.
The spat comes just days after Kenyan leader Uhuru Kenyatta attended the inauguration of Somalia's newly elected President Hassan Sheikh Mohamud, signalling a further improvement in often frosty ties.
Somalia also agreed to resume imports from Kenya of the narcotic leaf khat after a two-year ban, as part of a wider trade deal being forged between the East African neighbours.
Mogadishu had severed diplomatic relations in December 2020 after Nairobi hosted the political leadership of Somaliland but they agreed to reset ties in August last year.
Somalia's embassy said it was "unfortunate" Kenya had "intentionally invited" a person from Somaliland to Kenyatta's briefing to the diplomatic corps and had provided "equal privileges as that of a sovereign state despite the protest made by the Somali ambassador".
"In this regard, Somalia demands a full explanation of this violation of our sovereignty from the Republic of Kenya."
But the government of Somaliland, a former British protectorate which unilaterally declared independence in 1991, said it was "disappointed" by the action of the Somali ambassador.
"This clearly demonstrates the hatred and long-term enmity of Somalia towards the Republic of Somaliland and its people," its foreign ministry said in a statement.
Somaliland's independence declaration has not been recognised by the international community, leaving the Horn of Africa region of about four million people poor and isolated.
It has however remained largely stable while Somalia has been wracked by decades of civil war, political violence and an Islamist insurgency.
