Facebook has announced plans to open a software engineering centre in New York in early 2012.
The firm already employs an advertising team in the city. However, it is the first time the company has created a software base that is not on the US West Coast.
Reports also suggest the social network has bought Gowalla - a location-based "check-in" service.
The moves come ahead of an expected stock market flotation.
Facebook's chief operating officer, Sheryl Sandberg, announced the New York expansion plan at a press conference attended by the city's Mayor, Michael Bloomberg, and other officials.
"We are trying to grow at a clip that will allow us to get the very best people and integrate them," she said.
"We will be adding thousands of employees in the next year."
The new office will be headed up by Serkan Piantino. He previously led the engineering team behind Facebook's News Feed and helped develop its Timeline feature.
Ms Sandberg did not specify how many of the "thousands" of promised posts would be created in New York.
Reports suggest the firm has also taken over Gowalla.
Texas-based Gowalla is a two-year-old social network based around the idea of allowing users to "check-in" to locations and share pictures from their visits.
Members used to receive virtual "items" at certain check-in points. However, the company struggled against a larger competitor, Foursquare. In September it refocused its efforts on becoming a travel service, offering "social guides" to 60 cities, including London, Paris and Chicago, based on its members' postings.
At the end of last weekCNN reportedthat Facebook had bought the firm for an undisclosed sum and would move Gowalla's development team onto its Timeline feature.
Timeline turns users' Facebook profile pagesinto a digital scrapbooks, making it easier for users to view each others' life histories. The feature was announced in September, but has yet to be rolled out to many of the site's members.
Investing in location
Neither Facebook nor Gowalla have confirmed the takeover.
However, the All Things D website reported that Gowalla's chief executive, Josh Williams,had sent an email to investors.
"The ink on the deal is not dry, so our holding pattern is that we do not comment on rumours... A longer email will be sent soon," it is quoted as saying.
Facebook already had a location-based service built into its mobile device apps and website, but experts say the network may want to offer a richer experience.
"Facebook Places seems to work fairly well but they want to make a big play in this area," said Lee Bryant, the European managing director of Dachis Group, a social media consultancy.
"Location-based services are still in their early stages. Gowalla was interesting and slightly more story based than Foursquare, which Facebook may feel will help it strengthen its Timeline service."
Ready to float
Tech analysts expect Facebook to announce details of a share flotation in the New Year.
TheWall Street Journal has reportedthat the firm could raise $10bn through the sale, valuing the company at $100bn.
It quotes sources saying that the initial public offering (IPO) could be completed by June.
Facebook has declined to comment, saying it does not want to add to speculation about the move.