Mandela says the United States only went to the Security Council as an afterthought, but called the eventual decision to work through the United Nations "a welcome relief."
"We would want to urgently appeal to the US and its leadership to demonstrate their strength in the world by respect for those democratic principles they hold dear in their domestic affairs," Mandela told delegates at the African National Congress' party convention.
After strong lobbying from the US government, the UN Security Council sent weapons inspectors to Iraq to determine whether that nation has abandoned its efforts to produce biological, chemical and nuclear weapons.
As the inspectors continue their work, the United States has begun mobilising troops in the region for possible military action against the Middle Eastern nation.
Mandela, who also criticised Britain's support for US policy on Iraq and said he hoped the United States would refrain from unilateral action and respect the authority of the Security Council.