In another blow to the United States, the Islamic State beheaded American journalist Steven Sotloff, whom the militants had threatened to kill during the execution of journalist James Wright Foley, if America failed to reassess its Iraq policies.

Sotloff, a 31-year-old freelance journalist from Miami, was a hostage in Syria since August 2013. The executioner in the latest video appears to be the same man with the British accent who also supposedly beheaded Foley Aug. 19.

The militant held President Barack Obama responsible for the continued airstrikes in Iraq. "I'm back, Obama, and I'm back because of your arrogant foreign policy towards the Islamic State, because of your insistence on continuing your bombings and in Amerli, Zumar and the Mosul Dam, despite our serious warnings," the masked man said in the video titled "A Second Message to America."

Right after the execution of Sotloff, a British hostage, David Cawthorne Haines, appears at the end of this video, similar to what was shown after the killing of Foley.

An unnamed U.S. official told The Wall Street Journal that Haines had also likely been killed. However, this has not been immediately confirmed.

Prior to the execution, Sotloff makes what appears to be a scripted statement addressed to Obama. "Your foreign policy of intervention in Iraq was supposed to be for the preservation of American lives and interests. So why is it that I am having to pay the price of your interference with my life?"

Is Raqqa the Execution Place of Foley and Sotloff?

The video has striking resemblance to that of Foley's execution footage. Sotloff and Foley wore orange jumpsuits and the executioner is covered head to toe in black. The filming of the videos also appears to be in a similar arid and deserted area.

Elliot Higgins, the British founder of online journalism site Bellingcat and renowned investigative analyzer on chemical weapons use in Syria, says that the site of Foley's execution might be the hills south of the Syrian city of Raqqa, under IS control for over more than a year. Higgins said both videos possibly have been filmed in the same region, reports The Guardian.

Officials Determining the Authenticity of the Video

The authenticity of the video has not yet been confirmed by the White House officials yet.

"We have seen a video that purports to be the murder of U.S. citizen Steven Sotloff by the Islamic State of Iraq and the Levant, " White House National Security Council Spokeswoman Bernadette Meehan said. "The intelligence community is working as quickly as possible to determine its authenticity. If genuine, we are appalled by the brutal murder of an innocent American journalist."

However, Sotloff's family seems to believe the video is authentic.

"The family knows of this horrific tragedy and is grieving privately. There will be no public comment from the family during this difficult time," reports Reuters.

Pressure on Obama to Intensify Actions Against ISIS

Following the video, the U.S. lawmakers urged President Obama to intensify efforts to create a broad union of nations that would take on the Islamic State. Last week , the president said that Secretary of State John Kerry will go to the Mideast to get support from nations in the region.

"There is a growing awareness internationally that we have to form an unprecedented international program of cooperation," said Rep. Ed Royce of California, the Republican chairman of the House Foreign Affairs Committee, according to Bloomberg.

Reactions to Sotloff's Killing

The U.K. Prime Minister David Cameron condemned the execution of Sotloff, saying the act was "despicable and barbaric". He said, "...Terrorists speak for no religion. They threaten Syrians, Iraqis, American and British people alike and make no distinction between Muslims, Christians or any other faith."

Nancy Gibbs, editor of Time magazine, for which Sotloff contributed, said that he "gave his life so readers would have access to information from some of the most dangerous places in the world."

Miami-Dade County Mayor Carlos A. Gimenez said, "Today we mourn the death of Miami native son, Steven Sotloff, at the hands of the brutal and evil ISIS terrorists. Our deepest condolences go out to his parents and his entire family. The cruelty shown to Steven is in stark contrast to the courage and bravery he displayed both as a journalist and an American. Our hearts are with the Sotloff family at this time of grief, and we pray for an end to this terrorist violence."