Now diplomacy is making headway in containing nuclear threats in Iran and North Korea, he said in an Associated Press interview.

The former Army general suggested he will remain in public life somehow.

"I've still got some treadwear left on me," he said.

Powell plans to leave office early next year. President Bush has nominated White House national security adviser Condoleezza Rice to replace him.

International pressure is putting a "heat lamp on Iranian nuclear activity, and the whole world is now concerned about it," he said.

North Korea, Powell said, is a problem that time may help to solve.

"The president is committed to finding a political, diplomatic solution. We believe that ultimately North Korea will determine that it is their best interest," he said.

Powell said there are no plans to launch a military strike on Iran, which has suspected nuclear weapons facilities, or to take military action in North Korea. Bush linked the two countries with Iraq as an "axis of evil" in 2002.

"In the Pentagon, people are always thinking about the unthinkable," Powell said of a potential Iranian strike. "But there are no military plans about to be launched and there's no point in getting everybody excited about this."

The North Korean government is "constantly accusing us of having hostile intent," Powell said. "We have no hostile intent. We have no intent of invading. We have no intention of attacking North Korea."

As for Iraq before the war, Powell said claims about Saddam Hussein's weapons stockpiles were part of "the best information that the international intelligence community had" when he used it to lay out a case for war at the United Nations last year. He shrugged off a question about whether his personal credibility suffered when no weapons of mass destruction were found.