XCOM: Enemy Unknown is getting a sequel or story DLC, along with an iDevice port, Firaxis has revealed.

A brief teaser shown at PAX relayed a message from The Council, whose shadowy spokeman managed only the following before the signal was lost: “Hello commander. The war continues at great cost. We now believe another force is at work against us…”

Whatever that means, it is Firaxis’ “next big project”, said the developer.

In December the game received DLC called the Slingshot Content Pack, which added Council missions in China and a new character to the game, along with a handful of cosmetic customisations.

Meanwhile, XCOM: Enemy Unknown is being ported to iPhone, iPad, and iPod Touch by 2K China, under the guidance of Firaxis.

The iDevice version will be the complete game, except it will not feature as many maps – the result of file size limitations on the iPad.

Enemy Unknown lead developer Jake Solomon told Polygon that work began on the iDevice port almost a year ago, with Firaxis confident in the product after its successful transfer of Civilization Revolution to touchscreen devices.

"The touch interface is sort of uniquely suited to strategy games, especially turn-based strategy games," he said.

"I think that moving your soldiers feels super intuitive with touch controls."

“It was one of those things that was a challenge for us to figure out on consoles where you steer the cursor with the gamepad. It was actually much easier on the iPad because it mimics the PC in the sense that it's easier to steer your soldier, because all you do is look at the screen and click."

XCOM: Enemy Unknown will release in Autumn on iPad, iPhone, and iPod Touch.