Ulvaeus told Denmark's Ekstra Bladet tabloid on Wednesday that "it takes an extremely long time'' to make the video for the song with the avatars of the group members, adding "it has been delayed for too long.''
The band earlier said Ulvaeus, Benny Andersson, Anni-Frid Lyngstad and Agnetha Faltskog reunited to plan a virtual tour featuring digital avatars.
One of two planned new songs is entitled "I Still Have Faith in You''.
It's not yet clear if that's the song that will come out later this year.
ABBA shot to fame by winning the 1974 Eurovision Song Contest with Waterloo, and had big hits in the 1970s including Dancing Queen before splitting up in 1982.