British Prime Minister David Cameron on Tuesday condemned an Islamic State video apparently showing a terrorist beheading a second US reporter and threatening to kill a British captive as “despicable”.

“If verified, this is a despicable and barbaric murder,” Cameron said in a statement.

A video released on Tuesday appears to show freelance reporter Steven Sotloff dressed in orange and on his knees in a desert landscape. A masked man apparently carries out the beheading.

Sotloff’s life was threatened in the video that showed the murder of another American journalist, James Foley, last month.

The radical Islamist group threatened to execute British national David Cawthorne Haines next unless its demands were met, Site Intel Group, reported. It was not immediately clear who Haines was. Officials with the British Foreign Office declined to immediately comment.

“As I have said consistently over the last few weeks, ISIL [the group has previously been known by this name which is an acronym for the Islaimc State in the Levant] terrorists speak for no religion. They threaten Syrians, Iraqis, Americans and British people alike and make no distinction between Muslims, Christians or any other faith.”

Cameron expressed his sympathy with the family and friends of reporter Steven Sotloff, the second US journalist to be killed by the group in recent weeks.

The prime minister said he would hold a Cobra emergency meeting on Wednesday to “review these latest developments” and said the government would do all it could to protect its people from the jihadists.

Egypt’s foreign minister called for a “collective and international approach” against the “barbarism” of jihadist groups in Syria and Iraq.

In an interview with AFP, Sameh Shoukri said: “What we need is a collective and international approach that takes into account all the different elements required to fight this phenomenon: political, military and social.”

“It’s only with an international commitment that we can get rid of this barbarism,” added Shoukri, speaking to AFP on a visit to Paris.

Asked whether Egypt could envisage a possible military intervention against the extremists, the minister said Cairo was “ready to support the international community in terms of what might be decided on this subject” after a United Nations Security Council resolution.

“Each country will have a role to play but it’s still too early to know what,” he said.

France’s President Francois Hollande spoke of his “horror” following the apparent beheading of Sotloff.

In a statement, Hollande said: “This barbaric act, following the assassination of another journalist James Foley reveals the despicable nature” of the Islamic State.

He added that the “jihadist” movement “knew only terror”.