What is Obama's first-ever 'tweet'?

US President Barack Obama hit the send button of a computer key board to have his first ever "tweet" as he along with the First Lady visited the office of Red Cross in downtown here serving as disaster operations centre to coordinate humanitarian aid to quake-hit Haiti.

"We are just here to say thank you for the great work you're doing," Obama told members of the Red Cross as he and Michelle entered the of American Red Cross along with its chairman Bonnie McElveen-Hunter.

Obama and Michelle wearing a pink/black patterned dress and pearl necklace maneuvered through the maze of cubicles to speak personally with each staff member.

Stopping at a social media team desk, Obama laughingly hit "send" on a message just typed on Twitter: "President Obama and the First Lady are here visiting our disaster operation center right now."

This was followed by: "President Obama pushed the button on the last tweet. It was his first ever tweet!" Addressing the press pool, Obama said he had just learned that already $21 million in donations had been made to the Red Cross, via text message-a tribute to the generosity of the American people.

"I was just told that, just by Twitter, we've seen $21 million raised already, which just shows how generous the American people are in times of need," he said.

Speaking seriously with a group of staffers explaining their work, Obama said: "That's a lot of stuff to keep track of. Well, that's why we've got hot shots like you!"

Obama also announced that yesterday a United States Agency for International Development (USAID) search and rescue team pulled out 10 people from collapsed buildings in Port-au-Prince.

According to rescue officials, this is the largest number of rescues in a single day in decades of earthquake search and rescue efforts.

The rescue teams who led this effort, according to a USAID release, were from Los Angeles County, Miami Dade, and the City of Miami.