Foreign Secretary William Hague said he is determined to track down the terrorists behind the apparent killing of a British hostage.
"Responsibility for this tragic outcome rests squarely with the terrorists. I am grateful to the Nigerian Government for their unstinting help and co-operation," he said.
"We are utterly determined to work with them to hold the perpetrators of this heinous act to account, and to combat the terrorism which so blights the lives of people in Northern Nigeria and in the wider region."
More top news
Support for new parents has faced deep cuts in recent years - and some social workers warn it could lead to a rise in forced adoption.
Theresa May and Donald Trump will meet for talks at the World Economic Forum next week in Davos, in the Swiss Alps, Downing Street has said.
Cameras caught planes having a rough ride coming into land, after days of storms across northern Europe which left nine people dead.