Details have emerged of an agreement between Khartoum and Moscow for Russia to establish a naval base on Sudan's Red Sea coast.

The deal, signed last week, will allow Russia to keep up to four navy ships, including nuclear-powered vessels, in Port Sudan for the next 25 years.

Analysts say the move is part of Russia's attempt to reassert its geopolitical influence.

It's suffered a series of setbacks this year in its backyard, including the defeat last month of its traditional ally Armenia by Turkey-backed Azerbaijan.

In 2017, on his first visit to Russia, Sudan's former president, Omar al-Bashir asked President Vladimir Putin to "protect" his country from United States' aggression.

Mr Bashir has since been ousted from power and is being held in prison in Khartoum.