U.S. Senator Mark Udall apologized on Monday, citing his regret for invoking in a Saturday debate the two American journalists the Islamic State fighters beheaded.

Udall, a Democrat (Co.), put words in James Foley's and Steven Sotloff's mouths when he said that the journalists would tell them not to be impulsive in responding to the Islamic State threat.

Like Us on Facebook

"Horrible and barbarous as those executions were, don't be impulsive, come up with a plan to knock ISIS [Islamic State of Iraq and the Levant] back," he reportedly said in an untelevised debate with Republican challenger Cory Gardner in Colorado.

Udall has received massive criticism from the Republican camp since, for saying that the ISIS, also known as the Islamic State of Iraq and Syria (ISIS), does not pose an imminent threat to the United States.

"My intent was to emphasize the importance of taking the right next steps as we confront this serious threat," explained Udall.

Recovering momentum from Saturday's criticized remark, the Democrat explained how critical it is for the United States and its allies in the Middle East to tackle the terrorism in the region with a "tough and smart" approach.

Gardner did not counter Udall's statement at the debate. But slammed the Democrat on Monday, calling the incumbent's statement "outrageous" for putting words in the slain journalists' mouths.

Gardner said that it is deeply troubling that Udall views ISIS, a terrorist organization that is responsible for the genocides, ethnic and religious cleansing, crucifixions and countless beheadings in Syria and Iraq as "not an imminent threat to America."

Udall apologized an hour later, saying his remark was inappropriate.

Colorado's senatorial race is considered one of the tightest in the country. Recent polls show Udall and Gardner as neck-to-neck in a race that could determine which party will control the U.S. Senate.

TagsUS Senate elections 2014, Sen. Mark Udall, Democrats, Republicans, ISIS, ISIL, Islamic state of iraq and syria, Islamic State of Iraq and the Levant