Apple fans outside of the U.S. will have to wait a bit longer to get their hands on an iPad. Apple issued a statement today saying that due to the unexpected high demand for the iPad, it will have to delay the international release of the device by one month — until the end of May.

The announcement could have immediate impact on iPad developers. Many developers who created iPhone apps saw surprisingly strong adoption outside the United States, expanding their international market. A slowdown in sales outside the U.S. means that opportunity for the iPad will take longer to develop.

The company reports that it delivered more than 500,000 iPads in its first week of release, and it expects the high demand to remain steady throughout the next few weeks. Apple also needs to make sure there are enough 3G-equipped iPads available for U.S. customers, which will ship at the end of April.

Apple will announce international pricing on May 10, and international customers will be able to preorder iPads then as well. Of course, the delay isn’t stopping some international users from grabbing iPads on eBay at significantly marked up prices.

Since Tim Cook joined the company to run operations, Apple has become known for its smoothly running supply chain. So the delay in international sales, on top of the delay to Apple’s U.S. launch, which was pushed back from March to April, are surprising. Was Apple unprepared for the success of the iPad in the U.S.? Or is this a sign of kinks in its operations?

While the news is surely disappointing to international users, it’s a smart move by Apple to keep the American iPad market alive without setting units aside for an untested international market. Apple could have alternatively pulled a Nintendo and kept iPad stock low to stoke demand — just like many believed the console maker did with the Wii — but that could have been dangerous to the nascent tablet market.

It’s better to sell as many iPads to hungry fans as possible, particularly since Apple will face an onslaught of tablet competition this year from other manufacturers and platforms, like HP’s Slate and Dell’s Streak.