Afghanistan: Obama calls Karzai, says to conclude security pact with successor --- (Reuters) - U.S. President Barack Obama called Afghan President Hamid Karzai from Air Force One after departing Afghanistan and said he wants to conclude a security agreement with Karzai's successor, a senior administration official told reporters. -- Obama and Karzai discussed progress that had been made by Afghan security forces, the official said, and the U.S. president promised to inform his Afghan counterpart about his decision on how many U.S. troops will remain in the country after 2014 before making it public. -- Obama is expected to announce that decision soon. -- The call lasted 15 to 20 minutes, the official told reporters traveling on the president's plane.