Vivek Ramaswamy's presidential campaign has stopped spending money on television ads and does not have any TV ad reservations booked, according to his campaign and data from an ad-tracking firm.

As recently as the first full week of December, spent more than $200,000 on TV ads. Last week, it spent just $6,000 on ads — all of it on TV — figures from the firm AdImpact show.

Ramaswamy's campaign says it is still spending money on ads, just not on TV.

"We are focused on bringing out the voters we've identified — best way to reach them is using addressable advertising, mail, text, live calls and doors to communicate with our voters on Vivek's vision for America, making their plan to caucus and turning them out," Tricia McLaughlin, the campaign's press secretary told NBC News.

"As you know, this isn't what most campaigns look like. We have intentionally structured this way so that we have the ability to be nimble and hypertargeted in our ad spending," McLaughlin added.

The shift in strategy comes less than a month before the Jan. 15 Iowa caucuses — the first contest in the GOP presidential nominating process — and the Jan. 23 New Hampshire primary.

In early November, Ramaswamy's campaign announced that it planned — broadcast, cable, radio, digital and direct mail — in Iowa and New Hampshire. Since that announcement, the campaign has spent $2.2 million on TV, digital and radio ads, according to AdImpact.

More from NBC News:

Ramaswamy's rivals — former President Donald Trump, former U.N. Ambassador Nikki Haley, Florida Gov. Ron DeSantis and former New Jersey Gov. Chris Christie — are still buying up ads on the U.S. airwaves. In the same week that Ramaswamy spent just $6,000 on TV ads, Trump's campaign spent $1.1 million, followed by Haley's $1 million, DeSantis' $270,000 and Christie's $88,000.

That's in addition to the ad money being spent by the super PACs backing Ramaswamy's opponents.

SFA Fund Inc., a group backing Haley, spent $4.8 million on all ads last week. Fight Right, a group backing DeSantis, spent $1.3 million, followed by MAGA Inc.'s $987,000 and almost $700,000 by Tell It Like It Is PAC, which supports Christie.

American Exceptionalism PAC, which backs Ramaswamy, has not spent money on ads of any kind since October.