"When President Obama was sworn in, I continued going to the classified briefings as we had under George Bush, and it shifted from knowing classified tactical answers to more political answers in the briefings," he said. "So I'm frustrated that I don't think I know what's going on on the ground. I don't think I'm able to find out."

However, King did have some general reservations about Obama's Wednesday night announcement that he would withdraw 10,000 troops from Afghanistan by the end of this year. 

"It is the wrong tactic to tell our enemy that we are going to fight a war by the date on a calendar, by the numbers that are predicted," he said. "This tells them [the enemy], 'Go underground and wait us out.' "

King added that while he's "uneasy" about U.S. tactical objectives in Afghanistan, he has long believed the U.S. military will "accomplish those missions that are set out for" it.

But he also said he is wary about the nation-building component of U.S. operations. "I don't know about the progress of that, and I'd like to hear some input from the White House that gives me a higher level of confidence that we're ready for this move," he said.