Republican presidential candidate Jeb Bush speaks during a primary night rally on Feb. 9 in Manchester, N.H.(AP/Steven Senne)

The super PAC backing Jeb Bush's Republican presidential campaign is planning to increase its ad buy in South Carolina ahead of the Feb. 20 primary.

Right to Rise USA is pouring another $1.7 million into the Palmetto State in the next 10 days on top of the more than $10 million the group has already spent in the state, according to people familiar with the plans. The money will be spent primarily on television, radio and digital advertising.

The cash infusion is coming as the PAC is postponing the start of ad buys in seven states holding contests in March.

The group previously announced plans to air ads in Virginia, Georgia, Oklahoma, Tennessee, Texas, Michigan and Idaho. Those ad campaigns will start closer to March 1, freeing up some money to be spent in South Carolina sooner, said the people familiar with the plans, who asked for anonymity to speak frankly about campaign strategy.

Right to Rise currently has two ads in heavy rotation in South Carolina. The first stars former president George W. Bush touting his brother's record. The second ad attacks Florida Sen. Marco Rubio for a lack of legislative accomplishments. A similar version of that ad aired in New Hampshire in the closing days of the primary there.

As for the Bush campaign, it is currently only spending money on radio advertising in South Carolina and released a new message on Wednesday that also stars George W. Bush.