The U.S. ambassador to the United Nations is calling on Russia to use its influence with the Syrian regime to help get humanitarian aid to the besieged city of Homs.

Samantha Power gave a speech Monday during International Holocaust Remembrance Day. She said that just as Russian soldiers liberated Auschwitz in 1945, "the world again needs Russia to use its influence, this time to ensure that food reaches the desperate and starving people imprisoned in besieged Homs, Yarmouk, the Damascus suburbs and elsewhere."

During talks in Geneva, the Syrian regime and opposition reached a tentative agreement about the evacuation of women and children trapped in Homs before aid convoys go in. But no progress had been made on the ground by Monday night.