What you need to know:
- States can however go to the UN Security Council if another country fails to obey a ruling.
Somalia's president urged Kenya to "respect the international rule of law" after the UN's top court handed Mogadishu control of most of a potential oil- and gas-rich chunk of the Indian Ocean on Tuesday following a bitter row with Nairobi.
Kenya got only a small slice of the disputed tract of the sea off the East African coast in the ruling by the International Court of Justice (ICJ) based in The Hague.
In a televised speech following the ruling, Somalia's Mohamed Abdullahi Mohamed, who is widely known as Farmajo, said Nairobi should "see the decision of the court as an opportunity to strengthen the relationship of the two countries".
But with Kenya refusing to recognise the "biased" court's authority, all eyes will be on what Nairobi does next in one of the world's most troubled regions.
Somalia had dragged Kenya to the court in 2014 after years of efforts to resolve a dispute over the 100,000 square-kilometre tract failed.
"Since the day I was elected, we have faced political, diplomatic, security and economic pressure by the Kenyan leadership," Farmajo said.
"The verdict was a fair indication of the transparency of the International Court of Justice."
Judges unanimously ruled there was "no agreed maritime boundary" in force and drew a new border close to the one claimed by Somalia.
The ICJ's judgment is final and cannot be appealed, but the court, set up after World War II to rule in disputes between UN states, has no means of enforcing its rulings.
States can however go to the UN Security Council if another country fails to obey a ruling.
Nairobi says it has exercised sovereignty over the area since 1979.
The contested area is believed to contain rich gas and oil deposits, and also has important fishing rights. Nairobi has already granted exploration permits to Italian energy giant ENI but Somalia is contesting the move.