GOP presidential candidate Rick Santorum said Tuesday he is suspending his campaign.

He made the announcement at the Gettysburg Hotel in Gettysburg, Pa., talking about his young daughter’s illness and reflecting on the campaign.

His 3-year-old daughter Bella was taken to a Virginia hospital Friday with pneumonia. Santorum, a former Pennsylvania senator, left the campaign trail until this afternoon. The child has a life-threatening genetic disorder known as Trisomy 18.

“She’s a fighter,” said Santorum, standing beside his wife and children. “She’s doing exceptionally well.”

Santorum also faces an uphill battle against front-runner Mitt Romney in the race for the Republican presidential nomination. Five states, including Santorum’s home state of Pennsylvania, hold primaries April 24.

Romney is spending $2.9 million in TV ads in Pennsylvania. Romney is far ahead of Santorum in the race for delegates to the Republican National Convention and is the party’s likely nominee.

Romney said after Santorum concluded his speech at about 2:45 p.m: “Sen. Santorum is an able and worthy competitor, and I congratulate him on the campaign he ran. He has proven himself to be an important voice in our party and in the nation. We both recognize that what is most important is putting the failures of the last three years behind us and setting America back on the path to prosperity.”

Former House Speaker Newt Gingrich, who is still in the GOP race with Texas Rep. Ron Paul, also praised Santorum for his campaign.

“Rick has waged a remarkable campaign,” he said. ‘His success is a testament to his tenacity and the power of conservative principles.”

Gingrich also reiterated he is commitment to stay in the race to the party’s nominating convention in August in Tampa.

“I humbly ask Sen. Santorum’s supporters to visit Newt.org to review my conservative record and join us as we bring these values to Tampa,” he added. “We know well that only a conservative can protect life, defend the Constitution, restore jobs and growth and return to a balanced budget.”

Paul campaign spokesman Jesse Benton said: “Congratulations to Sen. Santorum on running such a spirited campaign. Dr. Paul is now the last – and real – conservative alternative to Mitt Romney. We plan to continue running hard, secure delegates, and press the fight for limited, constitutional government in Tampa.”