Update: 2K has told VideoGamer.com that the first piece of DLC is a timed Microsoft exclusive for 30 days.

Original: The first of several pieces of narrative-driven post-launch add-on content for The Bureau: XCOM Declassified will be released exclusively on Xbox 360, 2K has announced.

Further DLC will be released on all platforms.

"We take great pride in our track record of providing high-quality post-release content for our games," said Christoph Hartmann, president of 2K. "We will continue to expand the XCOM universe by telling original stories set in the paranoia-drenched Cold War era of The Bureau."

In addition, customers who pre-order The Bureau will receive a bonus campaign side-mission called Codebreakers.

In this mission, a top secret government communications facility responsible for intercepting and decoding the enemy's transmissions has gone radio-silent, leaving Special Agent Carter and his squad to make contact with personnel in order to bring the facility back online.

The Bureau: XCOM Declassified releases August 23 for Xbox 360, PS3 and PC.

Source: Press release