He described the situation there as catastrophic, and said that according to ICRC staff on the ground, thousands of people have taken to the streets and tension is running high in some neighborhoods.
The White House issued a statement Tuesday night from President Obama: "My thoughts and prayers go out to those who have been affected by this earthquake. We are closely monitoring the situation and we stand ready to assist the people of Haiti."
U.S. military and humanitarian services said they were ready to offer help, but officials said privately that they had to wait for a formal request from the Haitian government.
"The United States is offering our full assistance to Haiti and to others in the region. We will be providing both civilian and military disaster relief and humanitarian assistance and our prayers are with the people who have suffered, their families and their loved ones," Secretary of State Hillary Clinton said in Honolulu, Hawaii, where she was to make a speech on Asian relations.
"We are standing by to help in any way we can," said Crowley.
The U.S. Agency for International Development asked California Task Force 2, the Los Angeles County Fire Department's search and rescue team, and Virginia Task Force 1, sponsored by the Fairfax County, Va., Fire and Rescue Department, to prepare to deploy to Haiti to help with the recovery effort, should the country request assistance.
The Coast Guard had said that it would send out reconnaissance planes at first light today to assess the damage to the region. They also have four cutters in the area should a request be made for assistance.
"Everybody is just totally, totally freaked out and shaken," said Henry Bahn, a visiting official with the U.S. Department of Agriculture. "The sky is just gray with dust."
Bahn said he was walking to his hotel room when the ground began to shake.
"I just held on and bounced across the wall," he said. "I just hear a tremendous amount of noise and shouting and screaming in the distance."
Today French authorities said two aircraft with emergency aid and 120 rescue personnel are due to take off for Haiti from the Martinique Island and from Paris. There are 1,400 French nationals living in Haiti, 1200 of them are based in Port-au-Prince.
In Italy, the Civil Protection department together with the Foreign Ministry, the Defense Ministry and the Italian Red Cross are organizing a first-emergency medical team to leave for Haiti today on a C130 which will be carrying a camp-hospital.
The Pope appealed for aid to Haiti at the end of his weekly public audience, saying "I appeal to the generosity of all, so that our brothers and sisters do not lack real solidarity and support from the international community in their time of need and pain."
The ICRC spokesman Schorno said that they are still trying to work out if any relief flights would be able to land in Port-au-Prince. The main mission, he said, will be to provide medical personnel and supplies as well as tracing specialists, who help with evacuation, identification of the dead and re-establishing family links.
In the United States, Rose Leandre was anxiously trying to get through to any family members in her native Haiti on Tuesday evening.