The new iPhone 6 goes on sale on 19th September in United States and the company started taking online orders on 12th September.

Besides, the 5.5- inch iPhone 6 ‘Plus’ model has a waiting period of one month and the smaller version – iPhone 6, which has a 4.7-inch screen, remains available for delivery till 19th September, according to Apple’s website.

Online retailers Verizon and Sprint also showed shipment delays of upto six weeks on their respective websites. Apple said that the pace of orders has so far outnumbered all its previous iPhones.

“Response to iPhone 6 and iPhone 6 Plus has been incredible, with a record number of pre-orders overnight. Pre-orders are currently available online or through the Apple Store App,” Apple spokeswoman Trudy Muller said.

The Cupertino-based tech giant routinely grapples with iPhone supply constraints, particularly in years that involve a smartphone re-design.

The latest iPhones come with larger screens and some analysts had anticipated that production issues may keep a lid on initial runs.

Its suppliers had scrambled to get enough screens ready because the need to redesign a key component had disrupted panel production, supply chain sources told a news agency last month.

It was unclear whether the hiccup could limit the number of phones available to consumers, the sources said. Apple declined to comment on supply chain issues.

Apart from that, Chinese customers may also have to wait until the year-end before they can buy the iPhone 6. Apple is yet to set a release date for China, the world’s biggest smartphone market.

The company unveiled its latest iPhones along with a watch and a mobile payments service on Tuesday.