What you need to know:
- Russian investments in Sudan, especially in gold, and ties with security forces have remained shrouded in ambiguity.
As much of the West seeks to isolate Russia after it invaded Ukraine, experts say Moscow is boosting relations with its longtime African ally Sudan, eyeing its gold wealth and strategic location.
Khartoum has lost crucial Western support since army chief Abdel Fattah al-Burhan led a military coup last October, a move that triggered broad condemnation and punitive measures, including a suspension of $700 million in US aid.
On February 23, the day before Russia invaded its neighbour, a Sudanese delegation headed by powerful paramilitary commander Mohamed Hamdan Daglo arrived in Moscow for an eight-day visit.
The two sides discussed "diplomatic, political and economic topics", as well as "Russian-Sudanese national security... joint cooperation and counterterrorism", said Daglo, commonly known as Hemeti, at a news conference upon his return.
Sudan relied militarily on Russia under strongman Omar al-Bashir, who was ousted in 2019 following three decades in power marked by international isolation and crippling US sanctions.
Russian private companies have reportedly benefited from Sudan's gold mines by ramping up ties with the military and Daglo's powerful Rapid Support Forces, which emerged from the Janjaweed militias accused of atrocities during the Darfur conflict that erupted in 2003.
"Moscow has been following a clear and coherent policy... to serve its interests" in Sudan and in Africa more broadly, analyst Khaled al-Tijani said.
"Russian investments in Sudan, especially in gold, and ties with security forces have remained shrouded in ambiguity," he added.
Researcher Ahmed Hussein said that Daglo likely discussed in Moscow arrangements between his forces and "Russian (security) apparatuses with links in Sudan and Africa, especially Wagner Group".
Wagner, a Russian private military contractor with links to the Kremlin, has faced accusations of involvement in turmoil in Sudan's neighbours the Central African Republic and Libya, while French President Emmanuel Macron last month warned of the shadowy group's "predatory intentions" in Mali.
The European Council on Foreign Relations has said Wagner personnel were deployed in Sudan "to mining exploration sites" following a 2017 meeting between Bashir and Russian President Vladimir Putin, who agreed gold mining deals and negotiated the construction of a Russian naval base on Sudan's Red Sea coast.
Wagner personnel subsequently provided "a range of political and military assistance" to Bashir's regime, according to the ECFR.
Also in 2017, Russian mining firm M Invest gained preferential access to Sudan's gold reserves, according to the Carnegie Endowment for International Peace.
Three years later, the US imposed sanctions on Russian oligarch Yevgeny Prigozhin, who has links to M Invest and is believed to own Wagner, for "exploiting Sudan's natural resources for personal gain and spreading malign influence around the globe".
The ECFR said Wagner had formed "a triangle of Russian influence linking Sudan, the Central African Republic and Libya", reflecting "Moscow's strategic interest in expanding its Africa footprint".
Daglo's RSF has itself been involved in the conflicts in Libya and Yemen.
Threats 'matter little'
As for the planned naval base in the strategic city of Port Sudan, "the Russians need to get to warm-water ports, and the Red Sea is an integral part of that ambition," Hussein said.
In December 2020, Russia announced a 25-year deal with Sudan to build and operate the base, which would host nuclear-powered vessels and up to 300 military and civilian personnel.
The same month, Washington removed Khartoum's designation as a state sponsor of terrorism, a listing that had long crippled its economy.
In 2021, Sudanese military officials said the naval base deal was under "review" after certain clauses were found to be "somewhat harmful".
Daglo said the base was not on the agenda in Moscow but that Sudan was ready to cooperate "with any country, provided it is in our interests and does not threaten our national security".
Following Sudan's October coup, Russia told a UN Security Council meeting that General Burhan was needed to maintain stability, one diplomat had said on condition of anonymity.
Last week, Sudan joined 35 countries in abstaining from a UN General Assembly vote condemning Russia's invasion of Ukraine.
For researcher Hussein, Russia's growing interest in Africa "puts Khartoum in the eye of the storm -- turning it into a battlefield for an international conflict that goes far beyond its borders".
Many fear that Western opposition to the coup is pushing Khartoum further towards Moscow.
"We're basically offering Sudan to the Russians on a silver platter," one Western diplomat told AFP on condition of anonymity.
"The generals sustained themselves under the Bashir-era embargo, which is why threats of isolation matter little today."