WASHINGTON - The first U.S. Army infantry troops are heading to Haiti Thursday as the military ramps up what Secretary of State Hillary Rodham Clinton called "a full court press" to provide earthquake relief.

The first group of soldiers — a little over 100 — from the 82nd Airborne Division will leave Fort Bragg in North Carolina later Thursday, the Army said. The troops will find locations to set up tents and other essentials in preparation for the arrival of another roughly 800 personnel from the division on Friday.

They come on top of some 2,200 Marines, also to be sent, as the military prepares to help with security needs, search and rescue and the delivery of humanitarian supplies. More than a half dozen U.S. military ships also are expected to help, with the largest, the aircraft carrier USS Carl Vinson, arriving Thursday.

Appearing on morning network news shows after cutting short an overseas trip, Clinton said it's still too early to make a firm estimate of the number of deaths in the wake of Tuesday's devastating, 7.0 magnitude earthquake. But she said officials know that approximately 3 million people, including 45,000 Americans, have been affected and that "tens of thousands, we fear, are dead."

President Barack Obama, who earlier announced a wide-ranging U.S. assistance and relief effort, planned another public statement from the White House later Thursday.

Clinton noted that the small Caribbean country was still recovering, with help from Washington, the United Nations and other countries, from the damage wrought by last year's storms, saying a key challenge now is to "get people back into some semblance of normalcy." She called Haitians "resilient people" and said no one is giving up on them.

Before the earthquake, Clinton said, "We had a full government effort under the Obama administration to really help the people, and we were making progress. ... This is devastating on every level." She said the United States will do "everything we can to help this country rebuild."

In another interview, Clinton said, "We are doing all we can to figure out how to attack the devastation all around and this is going to be a long-term effort," from saving lives and providing food, water and medical supplies, to beginning the reconstruction process.

[snip]

Of the damage in Haiti, Clinton said "the depth and scope is unimaginable" and said the small country has been plagued by a "cycle of hope and despair."

She appeared on ABC's "Good Morning America," CBS's "The Early Show," and NBC's "Today" show.