NBC reports that President Obama has relieved Gen. Stanley McChyrstal of his command.

NBC chief Pentagon correspondent Jim Miklaszewski reports that it was unclear if McChrystal submitted a letter of resignation or whether Obama took the action.

Update at 1:24 p.m. ET: CNN is also reporting that the general is out as commander of U.S. forces in Afghanistan.

Update at 1:27 p.m. ET: The Associated Press, quoting unidentified sources, says Obama has tapped Gen. David Petraeus to take over as top commander of U.S. forces in Afghanistan.

Update at 1:40 p.m. ET: Obama, speaking in the Rose Garden, said he accepted McChrystal's resignation "with considerable regret but with certainty that it is the right thing for our mission in Afghanistan, for our military and for our country."

Update at 1:48 p.m. ET: He said that he relieved McChrystal of command "not out of any sense of personal insult." He said the general's action in giving the candid magazine interview, "undermines civilian control of the military that is at the core of our democratic system."

Update at 1:50 p.m. ET: At the same time, he praised McChrystal, saying, "he has earned a reputation as one of our nation's finest soldiers."

Update at 1:51 p.m. ET: He said the appointment of Petraeus to take command of international forces in Afghanistan "is a change in personnel, but not a change in policy."

Update at 1:53 p.m. ET: Obama, on several occasions, praised McChrystal for his military service. "It saddens me to lose the service of a soldier I have come to respect and admire," he said.

(Posted by Doug Stanglin)