Former Pennsylvania Sen. Rick Santorum announced Wednesday in an exclusive interview on Fox News’ "On the Record with Greta Van Susteren" he is suspending his 2016 presidential campaign and endorsing Florida Sen. Marco Rubio.

Santorum said he came to the decision after discussing it with his wife Karen after the Iowa caucuses. 

“We decided that we could be better advocates in supporting someone who shared those values and will do better in this race,” Santorum told Van Susteren.

While saying he does not “endorse lightly,” Santorum described Rubio as “the new generation, and someone who can bring the country together.” 

“We wanted to find a candidate that really espoused the values we believed in,” he said. 

The decision comes after a poor showing in Monday's Iowa caucuses. 

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Santorum came in 11th place and picked up just 1 percent of the Iowa vote, despite winning the caucuses when he ran for the Republican nomination four years ago.

Santorum is the fourth White House hopeful to drop out of the race this week. 

Earlier Wednesday, Kentucky Sen. Rand Paul announced he would suspend his bid, following former Arkansas Gov. Mike Huckabee in leaving the race. On the 

Democratic side, former Maryland Gov. Martin O’Malley, who placed a distant third in caucuses, also announced Monday he would drop out.

Fox News' Carl Cameron contributed to this report.