WASHINGTON, Sept 9 (Reuters) - A charter flight carrying U.S. citizens and other lawful permanent residents has safely landed in Qatar after leaving Afghanistan with the Taliban"s cooperation, the White House"s National Security Council said on Thursday, saying such evacuation efforts would continue. "The Taliban have been cooperative in facilitating the departure of American citizens and lawful permanent residents on charter flights... They have shown flexibility, and they have been businesslike and professional in our dealings with them in this effort. This is a positive first step," NSC spokesperson Emily Horne said in a statement.