Obama: Assad is a 'losing bet'

US President Barack Obama has imposed new sanctions on the governments of Iran and Syria as well as those who help them crack down on dissent and target citizens for violence through technology.

Mr Obama announced the sanctions at a speech at the US Holocaust Museum in Washington, DC, after he toured the museum with writer and Holocaust survivor Elie Wiesel.

"We see the Syrian people subjected to unspeakable violence, simply for demanding their universal rights," Mr Obama said. "We have to do everything we can."