Samoura, the first female second-in-command at the governing body of global football, urged the FIFA Council to "approve the decision to expand the World Cup" at its next meeting on October 23 in Shanghai.
"FIFA is confident that a 32-team World Cup would offer a highly competitive tournament," Samoura, who is Senegalese, wrote.
The recent World Cup in France featured 24 teams and a few lopsided scores in the group stage, notably eventual champions the United States thrashing Thailand, 13-0.
Two days before the final, FIFA president Infantino proposed expanding the tournament to 32 nations in 2023.
Infantino has already secured agreement for a 48-team men's World Cup from 2026 when the hosts will be the USA, Mexico and Canada.
Infantino said FIFA needed to discuss the question as "a matter of urgency."
FIFA has yet to select a host for the 2023 women's World Cup. The nine candidates are Australia, Brazil, Argentina, Bolivia, Colombia, Japan, South Africa, New Zealand and South Korea, potentially with North Korea.
Infantino said that if expansion as approved "we should re-open the bidding process and allow everyone to have a chance to organise or maybe co-host."