The Reds managed to complete the transfer of the 23-year-old on deadline day from Paris Saint-Germain on a long-term deal.
"Sakho is a top, top centre-half and that adds to the great centre-back pairings that we have already and it will give that depth," the Liverpool Echo quotes Ayre as saying.
"He's an important marquee signing for us. It was a difficult one for us to get, but I'm very pleased that we've been able to attract him to the football club.
"One of the things that Brendan said was that he wanted to add real depth and strength and Sakho is a Champions League player of great pedigree and experience."