The first wave of the operation will provide water, food, hygiene packs and counselling to children and adults in the various makeshift camps in Port-Au-Prince, Jacmel and other quake-affected regions of the devastated Caribbean island.
Plan International's Director of Humanitarian Response & Disasters, Roger Yates said the money would save the lives of children in the region.
"The situation out there is utterly beyond anyone's imagination. The needs of the children and their parents are immediate and will continue to be so for the foreseeable future," he said.
"Fortunately Plan has a lot of local knowledge, having worked in Haiti for more than 35 years, so we are in a strong position to help communities survive, recover and rebuild.
"This new money will be a real help but it's vital everyone gives what they can as the need will be far greater in the coming weeks and months."
Plan Haiti Director Rezene Tesfamariam said it was a race against time to save people trapped under the rubble.
"There are people still alive underneath - you can hear them crying for help, but time is running out. It is beyond the means of individuals to reach them," he said.
"As part of my work I have been travelling round the city to find out where we can provide assistance and I see dead bodies lying in the street everywhere."
Plan, which has been in the country since 1973, is working closely with government, emergency services and other organisations to respond to the immediate needs of children in the region and to assess the situation.
Plan staff reported severe damage in Jacmel and Croix-des-Bouquets, two of the areas where it operates.
Plan's UK office is appealing for funds to help protect children and provide the help and support they will need.
"Our priority is assisting children and their families and getting people at risk into safe accommodation wherever possible. Easing psychological trauma, which is not as obvious, will be very important as will ensuring child protection," says Plan UK's chief executive Marie Staunton.
Anyone wishing to make a donation or to find out more about Plan's work can visit www.plan-uk.org/haiti or freephone 0800 130 0230.
Plan staff are available for comment in Haiti but access to satellite communications is limited.For requests, please contact:
Alistair Clay +44 207 482 4982 (m) 07919 574180 firstname.lastname@example.org
Roger Yates, Director of Humanitarian Response & Disasters +44 (0) 77340 233 75 email@example.com
How the following Plan offices have raised the $1millon
Canada - $125,000
Japan - $30,000
Sweden - $300,000
Germany - $100,000
UK - $100,000
Finland - $100,000
US - $240,000
Australia - £100,000
Spain - $30,000
Plan, has operated in Haiti for 37 years and currently has projects in the following areas: Beudet , Cayes-Jacmel , Croix-des-Bouquets , Dolney , Fort-Liberté , Frères , Jacmel , Lavallée , Ouanaminthe , Trou-du-Nord - Children will be the hardest hit by this disaster. Homes and schools have been destroyed. Children are still trapped under rubble while others are wandering the streets traumatized.