The latest effort to end the brutal and bloody war in Syria opens Wednesday in Switzerland, but experts have little hope for a breakthrough.
U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov are leading the talks, along with the United Nations and representatives of the Syrian government and the main opposition.
But Syria's main regional ally, Iran, will not be there. U.N. Secretary General Ban Ki-moon canceled Iran's invitation when it refused to accept the goal of a transitional government in Syria - one that likely would exclude President Bashar al-Assad.
Lavrov called Ban's decision a mistake, but not a disaster. He says Iran's presence was essential for success.
Expectations for a breakthrough at the talks are low. President Assad has said he will not give up power.
The peace conference begins as smuggled Syrian police photographs emerged Tuesday. They show sickening images of what are said to be Syrian victims of torture, starvation, beatings and strangulation.
One war crimes lawyer says the pictures remind him of images from Nazi death camps.
State Department spokeswoman Marie Harf says the pictures are extremely disturbing and horrible to look at. She says they illustrate actions that would be serious international crimes.
Some information for this report was provided by AP, AFP and Reuters.