Rick Santorum
Former Pennsylvania Senator Rick Santorum speaks at the Republican Party of Iowa's Lincoln Dinner in Des Moines, Iowa, United States, May 16, 2015.REUTERS/Jim Young

Nearly four years after losing the Republican nomination to Governor Mitt Romney in 2012, Rick Santorum has decided to run for president again. The former Republican senator from Pennsylvania told ABC News's George Stephanopoulos that he is "ready" for the upcoming election.

"I'm ready to do this again," he said during the exclusive interview. "It's an exciting opportunity."

According to ABC News, the 57-year-old will formally announce his candidacy at an event in Cabot, Pennsylvania. Santorum is joining a crowded GOP field, which includes six official candidates and several undeclared contenders.

The former Pennsylvania politician, who will face stiff competition from those vying for the same conservative Christian votes, may have a better time securing the GOP nomination the second time around, ABC News noted.

"Obviously, we learned something from the last campaign," Santorum said. "Number one, we're gonna have more money." The 2012 Iowa caucuses winner added: "You gotta do well in Iowa. You gotta win on election night as opposed to two weeks later."

Due to the high volume of Republican candidates, and new rules for the first primary debate, Santorum may not be able to participate in the debate in August.

As previously reported by IBTimes UK, candidates will be allowed to participate in the Fox News-hosted debate if they place in the top 10 of the five most recent polls by 4 August.

While Santorum has not been polling as high as his fellow GOP candidates, he was not too concerned about the possibility of not participating in the debate. "It's early," he told ABC News. "I don't worry too much about where things are now."

The father of seven announced on Twitter that supporters can watch his "special announcement" today at 5pm EST on his website.