"I don't know whether he's actually submitted one (letter) yet or not," department spokesman Richard Boucher said. "I think all of us realize that the two of them ... have been a very successful team."
Powell announced his resignation Monday. Although it's unclear whether Armitage will remain, Boucher said: "It's like Bosnia. In together, out together."
Armitage played a key role, along with Powell, in solving global crises during the past four years.