Biden believes U.S. can evacuate all Americans by end of August, national security adviser says

President Biden's national security adviser, Jake Sullivan, said the president believes U.S. forces will be able to get all Americans who want to leave Afghanistan out of the country by Mr. Biden's self-imposed deadline of August 31. However, Sullivan said the U.S. does not know exactly how many Americans are in the country. 

"The president is committed to ensuring that every American who wants to leave Afghanistan gets out of Afghanistan. He believes that we can accomplish that by August 31," Sullivan told "CBS Evening News" anchor and managing editor Norah O'Donnell on Thursday.  Sullivan said the U.S. has the capacity to fly thousands of people from the Kabul airport to other countries each day. It's the responsibility of those fleeing to get to the airport themselves.