"There doesn't seem to be any shame about this among people who used to feel like you had to have some sort of decorum," Obama said in an interview that was posted on YouTube Saturday.
More than 6,000 people were killed in over three days when a Sudanese paramilitary group unleashed "a wave of intense violence" in Sudan's Darfur region in late October, according to the UN.
Officials familiar with the Pentagon’s assessments said this would represent a significantly more serious level of engagement than previous confrontations between Washington and Tehran.