Abba star Bjorn Ulvaeus has revealed details of the two new songs the group has reunited to record.

The Swedish foursome announced they were getting back together to make new music ahead of their digital avatar tour.

Arriving at the world premiere of Mamma Mia! Here We Go Again, he told the Press Association: “One of them is a pop tune, very danceable.

“The other is more timeless, more reflective, that is all I will say. It is Nordic sad, but happy at the same time.”

He added: “I think that exuberant quality of the two ladies (Agnetha Faltskog and Anni-Frid Lyngstad) together singing, that makes the saddest song a bit uplifting, anyway I think that is what happens and that is very organic, that isn’t calculated, that just happened that way.”

Bandmate Benny Andersson hinted that he also had a third song on his mind.

Lily James, Cher and Amanda Seyfried attending the premiere of Mamma Mia! Here We Go Again
Lily James, Cher and Amanda Seyfried attending the premiere of Mamma Mia! Here We Go Again (Ian West/PA)

He said: “Yeah it is but don’t tell anyone. If we do a third one, it won’t be out until we go on the road.”

Andersson also said it is unlikely there will be a third album, adding: “It’s good to have a reason to do what you do and this avatar tour is a reason to come up with something.

“Doing another album is like doing Mamma Mia 3, what is the point unless there is a good reason, good script, good environment? It is such a joyful experience, so that is a reason to do it.”

Andersson also said he was determined that any sequel to Mamma Mia would have value that was more than just financial, so he wanted to wait until there was a good script.

He said: “It was not until we said yes. The first one was a good film, we were all happy about that and obviously the studio wanted to do another one because it went so well, so they said we should do another one but for what reason? Artistic reasons?

“But they kept asking. Finally after eight years there was a script that everyone agreed on, so we said, ‘OK then, let’s do it’. I am happy with it, it’s good stuff. For me this has nothing to do with money, I have enough, I am good.”

Mamma Mia! Here We Go Again is released in UK cinemas on July 20.