U.N. Secretary-General Ban Ki-moon says new talks aimed to help end Syria's war shouldn't be held up by wrangling over whether President Bashar Assad stays or goes.

The U.N. chief says he's encouraged by the talks in Vienna aiming to revive a Syrian political process to end the war.

Ban said they "should not be held up over the future of one man." In Vienna, the U.S., Saudi Arabia and other allies softened calls for Assad's quick removal from power. Russia and Iran didn't rule out his eventual departure.

Ban spoke Saturday in Geneva after meeting with International Committee of the Red Cross President Peter Maurer. They urged greater respect for international humanitarian law in the wake of dozens of attacks on health centers in conflict zones this year.