President Obama has officially gone on the record as the first US President to support gay marriage.

Obama said he has been in the process of forming an opinion on the subject for quite some time, and has been influenced by gay staff members, family, and members of the military service.

Obama recalled interactions with his daughters in an exclusive interview with ABC News' Robin Roberts.

“It’s interesting, some of this is also generational,” he said. “You know, Malia and Sasha, they have friends whose parents are same-sex couples. There have been times where Michelle and I have been sitting around the dinner table and we’re talking about their friends and their parents.

"And Malia and Sasha, it wouldn’t dawn on them that somehow their friends’ parents would be treated differently. It doesn’t make sense to them, and frankly, that’s the kind of thing that prompts a change in perspective.”