The new group of approved members is comprised of Algeria, Ghana, Libya, Morocco, Serbia and Togo.
"Within three years, AIIB's membership has increased from the 57 founders to 93 approved members from almost every continent. This shows our member's commitment to multilateral cooperation and strengthens AIIB's role in the international financial community," said AIIB Vice President and Corporate Secretary Sir Danny Alexander.
"The growing membership of the Bank in Europe and Africa also reflects the importance for growth and development of inter-regional connectivity, especially sustainable infrastructure that opens access to new markets in Asia and beyond."
The six prospective members will officially join AIIB once they complete the required domestic processes and deposit the first capital installment with the Bank. Shares allocated to the new prospective members come from AIIB's existing pool of unallocated shares.
AIIB said it expects to continue welcoming new members in the future.