The National Security Council has confirmed the authenticity of the video released by ISIS yesterday depicting the beheading of American journalist Steven Sotloff, the second such video in two weeks. "Whatever these murderers think they'll achieve by killing innocent Americans like Steven, they have already failed," President Obama, speaking from Estonia, said Wednesday. "We will not forget, and our reach is long and justice will be served."

Sherif Mansour, a program coordinator at the Committee to Protect Journalists in New York, told the Wall Street Journal that Sotloff had been captured at the Turkish border of Syria in August of last year.

Sotloff's killing, so soon after the beheading of journalist James Foley, has increased pressure on Obama to escalate American attacks on the region. According to the Journal, more than 120 airstrikes have been ordered against ISIS targets in Iraq since Aug. 8.

More from the Los Angeles Times:

Obama has said he is considering striking Islamic State forces in Syria, although he acknowledged he hopes to more fully develop a strategy for such action as he consults with allies in coming days.

Asked Wednesday whether his goal was to destroy the group, also known as ISIL, or merely contain it, Obama tried to set realistic aims. He compared the group to Al Qaeda, saying "there's always going to be remnants that can cause havoc."

"We will not be intimidated," Obama said.

[Image via AP]