An RAF C17 cargo plane has arrived at a Paris airbase to help French military efforts to contain rebels in Mali.
The first of two planes will load up with French armoured vehicles and other equipment before flying to the West African state on Monday.
A second C17 is due to arrive on Sunday evening. No UK troops would be deployed in a combat role, Downing Street said.
France has attacked Islamist militants in Mali in recent days, to support the Malian government.
The first plane flew from RAF Brize Norton in Oxfordshire to the Evreux airbase where it will be loaded with French armoured vehicles and other equipment before flying to Bamako. It will make just one trip.
The second C17 will shuttle between Mali and France for the next few days.
The Minister for Africa, Mark Simmonds, indicated British personnel could play a role in training the Malian army through the European Union.
He said the UK was providing "only very limited strategic tactical support" in the form of the two C17 transport planes, in response to a French request.
The C17 has a much greater lifting capacity than the aircraft the French use, the BBC's Hugh Schofield in Paris said.
"There are no plans to extend the UK's military involvement at the moment," Mr Simmonds told the BBC News Channel.
Justifying the government's decision to help, he told Sky News there was a "thoroughly unpleasant regime" in the north of the country with "raping and sexual violence taking place" and children being forced into the military.
The move was agreed in a phone call between Prime Minister David Cameron and French President Francois Hollande on Saturday night, Downing Street said.
"The prime minister spoke to President Hollande... to discuss the deteriorating situation... and how the UK can support French military assistance provided to the Malian government to contain rebel and extremist groups in the north of the country," a spokeswoman said.
"The prime minister has agreed that the UK will provide logistical military assistance to help transport foreign troops and equipment quickly.
"We will not be deploying any British personnel in a combat role. They also agreed that the peacekeeping mission from West African countries needs to be strongly supported by countries in the region and deployed as quickly as possible.
"Both leaders agreed that the situation in Mali poses a real threat to international security given terrorist activity there."
The government's National Security Council (NSC) will discuss the situation when it meets on Tuesday.
Meanwhile, the French military has kept up its bombing of militant targets in Mali for a third day.
Defence Minister Jean-Yves Le Drian said the militants had suffered "significant" casualties and hangars and "sensitive sites" were destroyed.
French troops were deployed in Mali on Friday after its army lost control of a strategically-important town to Islamists who were advancing south. The rebels took control of a huge swathe of northern Mali last April.
France's decision to intervene so soon took many by surprise, as a UN-backed international force had not been expected to deploy in the west African state until the autumn.
French President Francois Hollande said France and Europe would be threatened by the creation of a "terrorist state".
Troops from neighbouring African states - Niger, Burkina Faso, Nigeria and Togo - are expected to arrive in Mali within days to support the government.