Kenya on Tuesday evening expressed "regrets" for inviting a Somaliland official to a diplomatic luncheon hosted by President Uhuru Kenyatta, where the Somalia ambassador was also a guest.
A Foreign Affairs ministry note sent to the Somali Embassy in Nairobi says the presence of the "Somaliland flag" at the State House meeting was "inadvertent and inappropriate."
"The ministry further wishes to reaffirm its recognition of one Federal Somali Government and the integrity of the Federal Somali State," it said.
The matter arose after Somalia's ambassador to Kenya Mohamoud Ahmed Nur 'Tarzan', walked out of the luncheon hosted by President Kenyatta for the diplomatic corps. A representative from the self-declared independent Somaliland liaison office was also among the guests, which the ambassador saw as inappropriate.
Somalia, which holds Somaliland as its territory, has never protested the establishment of the breakaway region's liaison office in Nairobi and has in the past permitted Nairobi to establish a consulate in Hargeisa, the capital of Somaliland.
On Tuesday, Mr Nur said he walked out because Nairobi had invited and granted the same diplomatic privileges to a diplomat from Somaliland, something he considered a violation.
The protest came just days after President Kenyatta travelled to Mogadishu to attend the inauguration of President Hassan Sheikh Mohamud and promised better ties between the two sides that had briefly cut diplomatic relations in December 2020. Somalia also pledged to reopen the miraa market for Kenya.
Somaliland declared its independence 30 years ago, but Somalia recognises it as one of its federal states.
On Tuesday, Somaliland's Foreign ministry said the Somali envoy had protested the "participation of the republic of Somaliland at the event."
"The Republic of Somaliland is a sovereign, independent and democratic country that aspires to live in peace and tranquillity with our neighbouring countries," it said.
However, no other country globally, including Kenya, recognises Somaliland's sovereignty. Nairobi has in the past said the final decision on the region's fate lies in dialogue between Mogadishu and Hargeisa.
The two regions were initially separately administered during colonial times, with Somaliland known as British Somaliland and Somalia known as Italian Somaliland. They merged in 1960 to form the Somalia Republic. In 1991, Somaliland unilaterally announced it had broken from the union.
Since then, Somaliland has run its own military, government, central bank and currency. Only Taiwan, which is internationally recognised as part of China, has ever recognised it.
In 2020, Somalia cut diplomatic ties with Kenya after President Kenyatta hosted Somaliland leader Muse Bihi. But Somalia didn't have the same protests when President Bihi toured Djibouti and Ethiopia.