The company said a surprisingly strong demand for the iPad in the US has forced it to stop taking orders till 10 May. The original UK launch date was scheduled for April.
The iPad is a 10-inch super slim touch-screen computer that weighs 0.68 kg and has 10 hours of battery life. The iBook application turns the iPad into an e-reader to browse newspapers, magazines and books.
In a statement, Apple admitted that although it had delivered more than 500,000 iPads in the first week of its US launch, the demand is far higher than its supply capability.
The company has also taken a large number of pre-orders for iPad 3G models for delivery by the end of April.