Critics accuse Mr. Bush and U.S. Defense Secretary Donald H. Rumsfeld of failing to send enough soldiers to secure the peace in Iraq after the invasion three years ago.
Powell said he gave the advice to now retired Gen. Tommy Franks, who developed and executed the Iraq invasion plan, and Rumsfeld while the president was present.
"I made the case to Gen. Franks and Secretary Rumsfeld before the president that I was not sure we had enough troops," Powell said in an interview on Britain's ITV television, according to a transcript released by the network. "The case was made, it was listened to, it was considered... A judgment was made by those responsible that the troop strength was adequate."
"And so it was not anything that was ignored, it was considered and a judgment was made by those responsible for making military judgments that the troop strength was adequate," Powell added.
On CBS' Face The Nation, current Secretary of State Condoleezza Rice said the president listened to questions from all of his advisers before finalizing the war plans.
"If there were questions about troop levels, they were raised," Rice told Bob Schieffer. "The president was able to ask the Joint Chiefs of Staff directly whether or not the plan was executable, whether or not the resources were there. I was in that meeting when he asked the Joint Chiefs of Staff, and they said 'yes.'"
Powell, who served as chairman of the U.S. Joint Chiefs of Staff during the 1991 Gulf War, is known for his belief in deploying decisive force with a clear exit strategy in any conflict.
"The president's military advisers felt that the size of the force was adequate, they may still feel that years later. Some of us don't, I don't," Powell said. "In my perspective, I would have preferred more troops but you know, this conflict is not over."
"At the time the president was listening to those who were supposed to be providing him with military advice," Powell said. "They were anticipating a different kind of immediate aftermath of the fall of Baghdad, it turned out to be not exactly as they had anticipated."
Rice countered on Face The Nation by saying troop levels is an topic for historians to argue later.
"We are in a phase now where we see that the number of foreign forces is not really the issue, the number of coalition forces is not really the issue," she said. "The issue is what can the Iraqis contribute to their own security."
Rumsfeld has rejected criticism that he had sent too few U.S. troops to Iraq, saying that Franks and two other generals who oversaw the campaign's planning, John Abizaid and George Casey, had determined the overall number of troops, and that he and Mr. Bush agreed with them.
Powell also said in the interview he believed it was "quite appropriate" for the international community to seek to pressure Iran not to continue nuclear enrichment activities.
However, he said the "menu of sanctions could be quite limited...the ones that could get through the (U.N.) Security Council."
"We are far from a point where any prime minister or president has to sit down and say it's time for an ultimatum or something more drastic will happen," Powell said. "You never take a military option off the table, it's always an option, but I think we are far from any consideration of using such an option."
As of Saturday, April 29, 2006, at least 2,399 members of the U.S. military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count. The figure includes seven military civilians. At least 1,886 died as a result of hostile action, according to the military's numbers.
The British military has reported 104 deaths; Italy, 30; Ukraine, 18; Poland, 17; Bulgaria, 13; Spain, 11; Slovakia, Denmark three; El Salvador, Estonia, Netherlands, Thailand, two each; and Australia, Hungary, Kazakhstan, Latvia, Romania, one death each.