The Sun has cited a Whitehall source as saying that British Defense Secretary Gavin Williamson was outraged after Paris said that London will have to pay £2 million ($2.5 million) so that the UK military can fly spare parts and kits to the Mali mission on French transport aircraft.
"We could not believe it. They begged for help, we give it, and then they want to charge us for keeping the mission running. The French can't fight their own wars — now they won't even help out those who help them. It sent Williamson livid — he threatened to ground the whole fleet," the source stressed.
For its part, the UK Defense Ministry, in a statement on Saturday, pledged to "continue to strengthen our deep defense relationship with France."
The remarks came after three Royal Air Force (RAF) Chinook helicopters and almost 100 British troops were sent to Mali last month to add to France's anti-jihadi effort there.
Currently, French servicemen are present in Mali as part of the ongoing anti-insurgent Operation Barkhane, which started in 2014.
In the past few years, Mali has suffered from a surge in violence as jihadist groups continue to exploit rebels from nomadic Tuareg tribes so as to gain control over the northern part of the country, which remains mostly lawless due to separatist activities.
In 2012, a Tuareg insurgency against the government triggered France, Mali's former colonizer, to intervene at the request of the country's authorities.
The UN Multidimensional Integrated Stabilization Mission in Mali (MINUSMA) has about 12,000 peacekeepers and was established by a UN Security Council resolution on April 25, 2013, alongside France's Operation Serval that ended later that year.
The UN mission's aim is to stabilize the country and protect civilians from jihadi activity in the region.