President Obama is scheduled to deliver remarks at the prayer service, the White House announced Wednesday. First lady Michelle ObamaMichelle LeVaughn Robinson ObamaHillary Clinton’s sorry apology is why she’s no champion for women Obamas send handwritten note to Parkland students: 'We will be there for you' Smithsonian moves Michelle Obama portrait to larger space over high demand MORE will also attend the event.

Romney, the former governor of Massachusetts, was invited by the state's current head, Gov. Deval Patrick (D). Other former governors, including former Democratic presidential nominee Michael Dukakis and Gov. William Weld will also be in attendance.

Romney has already extended his condolences to the victims of the attack in a post to the social media network Twitter.

Romney's son, Tagg, said that the perpetrator of the Boston Marathon bombing had "messed with the wrong people" in an interview with CNN the morning after the attack.

"It's such a cowardly act, whoever did this," Tagg Romney said. "Then you see the warmth of the first responders, and the people around who rushed to the scene. Such a contrast to their bravery. It just really is a family event. And it's the best of Boston. It's wonderful to see how people have been responding and how people are pulling together."