Amazon has revealed two new tablet computers, both of which will feature its Alexa virtual assistant for the first time.

The technology giant has announced that new versions of its Fire 7 and Fire HD 8 tablets will feature the voice-activated assistant, which first appeared in its Echo smart home speaker.

The Fire 7 will come with 12 hours of battery life and 16GB of storage, Amazon said.

Kids Edition, Amazon's range of tablets for children, has also been updated to include new versions of the 7 and HD 8.

Amazon says it believes it can compete with the likes of Apple's iPad by offering "premium products at non-premium prices."

The company's general manager of Fire Tablets, Kevin Keith, said: "We think customers should expect more from their tablet - better hardware, more features, access to tons of great content - but shouldn't have to pay a premium for it.

"Our approach is to offer premium products at non-premium prices."

The inclusion of the Alexa smart assistant marks the first time Amazon has added the software to a device that isn't one of its Echo speakers.

Tablet-users will be able to control their device using their voice via Alexa, as well as to ask questions and receive news, sport and weather updates from the assistant.

"The all-new Fire 7 is thinner and lighter, offers an improved display, longer battery life and better Wi-Fi connectivity, while keeping the same low price of $49.99," Mr Keith said.

"For only $30 more, the all-new Fire HD 8 offers a vibrant 8in HD widescreen display, up to 12 hours of battery life, faster performance and 16GB of storage."

The company's Kids Edition tablets are designed to have enhanced internet security settings and stronger filters, ensuring only safe content is seen by younger users.

The Fire for Kids Unlimited schemes, included with the tablets for a year, also gives access to educational apps.

Parents are also able to control the amount of time their children can access gaming and entertainment content.

The wider rollout of Alexa is further evidence of Amazon looking to increase the number of third-party devices that feature the software.

On Tuesday, smartphone giant HTC announced it would include the voice-activated assistant on its new flagship smartphone, the U11.