The U.S. is vowing to stick with the mission in Afghanistan, despite the deadly aftermatth of Koran burnings at a U.S. base.

FOX News Radio's Lisa Brady has more in our ongoing series on national security.

Securing America:

Since the U.S. Military admitted improper disposal of religious materials in Afghanistan, including Koran burnings, four Americans have been among those killed by extremists.

Little: "Anyone who believes they can weaken our resolve through these cowardly attacks, is severely mistaken."

And Pentagon Spokesman George Little says progress is being made on broader objectives. Objectives reaffirmed by the White House.

Carney: "The need to disrupt, dismantle, and defeat al-qaeda remains. The need to prevent Afghanistan from being a haven for al-qaeda to launch attacks against the United States remains."

White House spokesman Jay Carney says the goal remains, turning over the lead to Afghan forces by the end of 2014.

Lisa Brady, FOX News Radio.