Mali says it has cut diplomatic relations with Ukraine, after a military official suggested Kyiv had played a role in deadly fighting near the Algerian border last month.
Dozens of Malian soldiers and mercenaries from Russia's Wagner group were killed in days of clashes with Tuareg separatist rebels and fighters linked to al-Qaeda.
Andriy Yusov, a spokesman for Ukrainian military intelligence, said last week that the rebels had been given the "necessary information" to conduct the attacks.
A top Malian official, Colonel Abdoulaye Maiga, said his government was shocked to hear the claim and accused Ukraine of violating Mali's sovereignty.
Yusov's comments "admitted Ukraine's involvement in a cowardly, treacherous and barbaric attack by armed terrorist groups" that had led to the deaths of Malian soldiers, Col Maiga's statement said.
Mali has decided to break off relations "with immediate effect", he said.
Last week, Mali's army admitted it had suffered “significant” losses during several days of fighting earlier that erupted on 25 July.
The clashes took place in the desert near Tinzaouaten, a north-eastern town on the border with Algeria.
Reports say the Malian and Russian forcers were ambushed by Tuareg rebels and fighters from al-Qaeda affiliate Jamaat Nusrat al-Islam wal-Muslimin while waiting for reinforcements, after retreating from Tinzaouaten.
Neither Mali’s military nor Wagner - which has since morphed into a group called the Africa Corps - have given exact figures, but the estimated death toll for Wagner fighters ranges from 20 to 80.
The Russian mercenary outfit's losses are thought to be the heaviest it has suffered in Mali since it began helping the military government fight the insurgents two years ago.
Wagner has acknowledged that one of its commanders was killed and a Russian helicopter was downed in "fierce fighting", saying they had been attacked by around 1,000 fighters.
Tuareg-led separatists claimed on Thursday they had killed 84 Wagner mercenaries and 47 Malian soldiers.
More than a decade ago, Mali's central government lost control of much of the north following a Tuareg rebellion, which was sparked by a demand for a separate state.
The country's security was then further complicated by the involvement of Islamist militants in the conflict.
When seizing power in coups in 2020 and 2021, the military cited the government's inability to tackle this unrest.
The new junta severed Mali's long-running alliance with former colonial power France in favour of Russia, in a bid to quell the unrest.