Ambassador Oksana Markarova says Ukraine will be "responsible" in using U.S.-supplied weapons
Days after the U.S. said it would be sending controversial cluster munitions to Ukraine to aid in their fight against Russia, Ukrainian ambassador to the U.S. Oksana Markarova tells "Face the Nation" that Ukraine will be as "responsible" with these weapons as they are with all other U.S. and European supplied weapons.