Days after Islamist militants publicly executed American journalist James Foley, the United States says it tried unsuccessfully to rescue Foley and others captured by ISIS.

In a statement Wednesday, White House officials said that earlier this summer, President Obama authorized a mission to recover American hostages in Syria.

Despite the Defense Department's best efforts, the mission was not successful due to insufficient intelligence.

No specific details of the operation will be released, but the White House said Wednesday evening that "the United States will not tolerate the abduction of our people and will spare no effort to secure the safety of our citizens and to hold their captors accountable.”