Apple has made the iPhone 4 available to pre-order from its online store.

According to the company's website, the white handset is currently unavailable for pre-order. However, Brits can get their hands on a black version.

The 16GB handset is priced at £499, while the 32GB phone costs £599. The handsets are SIM-free, which means you'll still need to obtain a SIM from a UK mobile network before you can start using the device.

Apple says the iPhone 4 includes free shipping and will be delivered on June 24. Brits are limited to purchasing two handsets per person.

Those looking to purchase the handset through a mobile network on a monthly tariff are still waiting to find out how much they will have to pay.

Yesterday Vodafone's charges were leaked online, but were quickly removed. The mobile network also refused to confirm the prices.

Meanwhile, O2 has released details of the tariffs the iPhone 4 will be available on but has yet to reveal how much customers will need to contribute towards the handset.

T-Mobile, Orange and 3 are also stocking the handset in the UK. However, all three networks have yet to reveal pricing details.

Apple's latest smartphone was unveiled by Steve Jobs last week at the company's Worldwide Developers Conference (WWDC).

The new handset, which features an all-new design, has "well over 100 new features" including an HD screen, video calling, a gyroscope, a new iMovie app and countless other upgrades.

Check out the latest up-to-date information on iPhone 4 pricing and networks.

See also: O2 unveils iPhone 4 early upgrade offer