The GOP-aligned American Crossroads has reserved $1.1 million in North Carolina ahead of the state's competitive primary, a sign they're looking to boost establishment GOP pick Thom Tillis. 

Crossroads has reserved the airtime in April in the expensive Raleigh and Charlotte markets ahead of the early May primary.

Crossroads Political Director Carl Forti confirmed the buy, but wouldn't discuss whether the group aims at bolstering Tillis in the race.

"We can confirm $1.1 million reserved in Raleigh and Charlotte starting April 1. No comment at this point on the content [of the ads]," Forti told The Hill in an email.

Tillis, the North Carolina House speaker, is battling physician Greg Brannon (R), a Tea Party favorite, and a number of other GOP candidates in the race. He needs to win 40 percent of the vote to avoid a primary runoff, and the few public polls on the race have shown him to be well short of that mark even though his is the only candidate who's been on the air with ads.

Establishment Republicans have been pulling hard for Tillis in the race, seeing him as their best chance to defeat vulnerable Sen. Kay HaganKay HaganLinking repatriation to job creation Former Sen. Kay Hagan in ICU after being rushed to hospital GOP senator floats retiring over gridlock MORE (D-N.C.) in the GOP-leaning state. Karl Rove, one of Crossroads's founders, has headlined fundraisers for Tillis, as have Senate Minority Leader Mitch McConnellMitch McConnellStudy: Trump tops recent GOP presidents in signing bills in first 100 days Senate passes stopgap funding bill to avert shutdown Let’s never talk about a government shutdown — ever again MORE (R-Ky.), Sen. Richard BurrRichard BurrTrump voter who cast ballot illegally won’t be charged Burr: US in new Cold War with Russia Senator: No signs of GOP 'slow-walking' Russia investigation MORE (R-N.C.) and a number of other Republican power players.

This post was updated at 12:25 p.m.