Somaliland opened a representative office in Taiwan on Wednesday, returning the favour from Taiwan's office in Somaliland which opened last month.
Both are unrecognised, but de facto sovereign territories, and have found common ground in their isolated international status.
"Taiwan and Somaliland shared the commitment to safeguarding the values of freedom, democracy, justice and the rule of law", said Joseph Wu, Taiwan's foreign minister.
"We both face external pressures, but both proud of our sovereignty and ready to defend it."
The deepening relationship has sparked anger in Somalia, which described the move as a "reckless attempt" to infringe on its sovereignty, while Beijing accused Taipei of separatism.
"Our relations is based on the spirit of mutual assistance that will never do any harm whatsoever to the interests of other countries," Mohamed Hagi, Somaliland's representative in Taiwan, declared.
"But rather contributed to the international peace and improving economic activities. "
Only 15 countries diplomatically recognise Taiwan over Beijing, which claims the island as its own territory.
But many nations maintain embassy equivalent trade offices in Taipei.
Taiwan and Beijing have been fighting a diplomatic arm-wrestling match for decades, in which each side tries to poach the other's allies.
Somaliland, which is not officially recognised by any other nation, declared independence from Somalia in 1991 and has thrived as a comparative beacon of stability.