Amazon is in the advanced stages of placing its second headquarters in Northern Virginia, sources close to the matter told The Washington Post, as the retail giant zeroes in on a self-imposed deadline to make the closely watched decision.

The Post reported on Saturday that Amazon has held detailed discussions about the possibility of opening its second outpost in Crystal City, a residential and business area strategically positioned south of the nation's capital. Amazon is said to be mulling how quickly it could move employees, its physical plant and how it could make the decision public, people close to the process told the publication.

Amazon's planning was more in-depth than it has had with other potential locations in Northern Virginia, and other cities across the U.S., The Post stated. Yet on Sunday, The Wall Street Journal reported that the tech giant's list of potential finalists included Dallas and New York City.

In fact, the retail behemoth is said to be so serious about Crystal City that the area's premier developer, JBG Smith, has pulled some of its buildings off the leasing market to make way for Amazon, The Post reported, citing unnamed public and private officials close to the process. It's possible that Amazon may also be in similar talks with other cities considered finalists, the report cautioned.

Separately, sources told CNBC that Amazon and local officials had a "very productive" and "very long" conference call on Friday. A potential incentive package may include a "very generous" transportation incentive to alleviate traffic fears, as well as educational aspects to ensure Amazon has a pipeline to a skilled workforce.