WASHINGTON -- The National Republican Senatorial Committee is escalating Georgia's U.S. Senate race ad war with $2.5 million worth of television ad time in the next few weeks, according to two people monitoring ad buys in the state.

The buy runs for five weeks entirely in Atlanta starting Tuesday and appears to be the first strike of the general election for the NRSC anywhere in the country. It's the latest sign that the race between Republican David Perdue and Democrat Michelle Nunn is firmly on the national radar, and the GOP is taking the fight seriously.

The NRSC, which would not officially confirm the Georgia buy until the public paperwork is filed, has reserved TV air time in five other states but is not yet on the air in any of them. The committee's biggest TV reservations so far have been $2.66 million in Alaska, $2.59 million in North Carolina and $2.20 million in Colorado.

Perdue has to replenish his campaign bank accounts after a lengthy primary season. He attended an NRSC fundraiser in Washington last week. Nunn is airing her own ads but is being attacked by the Ending Spending Super PAC and, likely soon, the NRSC. A copy of the ad is not yet available, but such outside buys typically are attack ads.

As of December, the Nunn campaign predicted the NRSC and its cross-aisle counterpart, the Democratic Senatorial Campaign Committee, each would spend $8 million in all, according to internal memos.