Amazon unveiled plans on Tuesday for a major expansion in Boston's Seaport District, promising thousands of new technology jobs even as the city remains in contention for the company's coveted second headquarters.

The Seattle-based company announced Tuesday that its expansion in the Seaport District will create an additional 2,000 jobs, including machine learning, cloud computing and robotics engineering.

"GE has promised to bring 800 jobs to their new headquarters, so that’s almost three times what GE says they’re going to bring," Boston Globe business reporter John Chesto said Tuesday.

Back in January, the company began negotiations with a developer to lease office space in the area, which would be in addition to existing Amazon offices in Boston and Cambridge. The company said with its customer fulfillment facilities, Amazon has created more than 3,500 jobs in Massachusetts since 2011.

"In just a few years, we’ve grown from a handful of software developers and scientists to a team of more than 1,200, inventing new capabilities and products on behalf of millions of customers around the world," said Rohit Prasad, Amazon's, vice president and head scientist of Amazon Alexa, who is based in the Boston area.

According to a news release, the "Tech Hub" team will be focused on Alexa, Amazon Web Services and Audible.

Gov. Charlie Baker and Boston Mayor Marty Walsh both said they welcome the expansion.

"Amazon's expansion in the Seaport will bring thousands of new jobs to the Commonwealth and build upon the hundreds of jobs they already have here in research and development, fulfillment centers and robotics," Baker said.

"This project is a tremendous vote of confidence in our economy, and will be a welcome addition to Boston’s growing and thriving workforce and business landscape," added Walsh.

Amazon says the 430,000-square foot office space is expected to open in 2021.

The expansion has only fueled anticipation over which city Amazon will choose for its second headquarters, known as HQ2, which would bring 50,000 new jobs.

Some suggest the expanded tech hub could be a nod toward a future Seaport campus. But Chesto says “Amazon is saying this has nothing to do with their HQ2 search.”

Boston remains on the shortlist for the company's second headquarters, along with New York, Chicago, Austin, Atlanta, Miami, Los Angeles, Philadelphia and Washington, D.C. 

The city's preferred site for the larger project is Suffolk Downs, a former horse racing venue in the East Boston neighborhood, near Logan International Airport. But other sites are being considered as well, including one in the neighboring city of Somerville.

But either way, many see this latest expansion as a big win for the city.

"We call it HQ3, because there will be thousands of people," Chesto said. "They actually have an option to add another 2,000."

So while Boston continues to wait for the big news, this latest headline doesn't hurt its growing brand.

"Now you're seeing the Seaport become also a tech center of sorts," Chesto said. "So this only adds to our reputation."

A decision on Amazon's HQ2 location is expected later this year.