Anwar received a United jacket, which he quickly put on to show his support for the club.
ASEAN All-Stars head coach Kim Sang-sik and skipper Sergio Aguero, who shares his name with Manchester City's legendary striker, also presented a signed shirt to the Malaysian leader.
Youth and Sports Minister Hannah Yeoh, FIFA council member Tan Sri Hamidin Mohd Amin and ASEAN Football Federation president Major General Khiev Samet were also among those who attended.