Answering criticism with cash, Saudi Arabia on Tuesday swooped in to address the humanitarian crisis caused by the Sunni insurgency in Iraq, providing $500 million to the United Nations to help the more than one million Iraqis whose lives have been uprooted by the mayhem of recent weeks.

Saudi Arabia’s ambassador to Washington, Adel al-Jubeir, said in an interview Tuesday night that the Saudi contribution would be distributed through the United Nations “as expeditiously as possible.” The assistance, he said, would be provided to all Iraqis regardless of religion, sect or ethnicity.

The Saudi donation was one of the largest single contributions to United Nations humanitarian relief, far eclipsing the figure of $312 million in emergency funds that the United Nations had sought to deal with the suddenly enlarged Iraq crisis.