British Prime Minister David Cameron on Saturday welcomed France's military intervention in Mali, saying he was deeply concerned about recent rebel advances.
Cameron also offered condolences to the families of a French hostage believed killed and two soldiers either killed or missing in a rescue attempt in Somalia and said it showed the need to fight terror in Africa.
"I am deeply concerned about the recent rebel advances in Mali, which extend the reach of terrorist groups and threaten the stability of the country and the wider region," Cameron said in a statement.
"I welcome the military assistance France has provided to the Malian Government, at their request, to halt this advance."
France sent troops on Friday to help Malian forces hold back a rebel advance towards the capital Bamako, and on Saturday Paris announced that a French military pilot had been killed.
Cameron said the developments "show the need to make urgent progress in implementing UN Security Council resolutions on Mali, and ensure that military intervention is reinforced by an inclusive political process leading to elections and a return to full civilian rule."
Meanwhile in Somalia, a failed commando raid to free a French hostage held since 2009 left one French soldier dead and another missing, while "all indications" were that hostage Denis Allex also died, French officials said.
"I would also like to send personal condolences to the families of the French hostage killed in Somalia, and those of the two soldiers either killed or missing in the rescue attempt," Cameron said.
"Last night's tragic events underline how essential it is that we work together to combat terrorism in Africa.