The UK has agreed to help transport foreign troops and equipment to Mali amid French efforts to contain rebels.
France has attacked militants in Mali to support the Malian government, and has attempted to rescue a French hostage in Somalia, in recent days.
The UK is to provide two transport planes but No 10 stressed no UK troops would be deployed in a combat role.
Minister for Africa Mark Simmonds has indicated British personnel could play a role in training the Malian army.
He said the UK was only providing "very limited strategic tactical support" in the form of two C-17 transport planes, in response to a French request.
"There are no plans to extend the UK's military at the moment but there are discussions that are taking place that we're waiting for scrutiny from Parliament to, through the European Union, provide training support for the African Union and Ecowas [Economic Community Of West African States] to enable them to give the training they require to push the Islamists out of the northern part of Mali," Mr Simmonds told the BBC News Channel.
The move to transport foreign troops and equipment was agreed in a phone call between Prime Minister David Cameron and French President Francois Hollande, Downing Street said.
"The prime minister spoke to President Hollande this evening 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, President Hollande has ordered security is stepped up around French public buildings and transport following the operations in Mali and Somalia.
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.
The central town of Konna has since been recaptured, the Malian government says.
Then, French commandos went into action in Somalia, swooping on the town of Bulo Marer in an attempt to free Denis Allex, who was kidnapped in July 2009.
A battle erupted with al-Shabab militants and, according to President Hollande, the operation failed "despite the sacrifice of two of our soldiers and probably the assassination of our hostage".