"[Bolivia and Cuba] are part of the group that has received an invitation. We are sure that everything will work out in terms of them connecting [to BRICS] as partner states," Ryabkov told the Izvestia newspaper.
The deputy minister also said that the coordination process with invited states is still ongoing but will be completed by the end of the Russian presidency in the organisation.
"There are, of course, no backing out, and there can be none. For all invited countries, this is a big, serious prospect, so there are only a few days left, after which the relevant list will be made public," Ryabkov added.
BRICS leaders finalised the list of partner countries at the summit in the Russian city of Kazan from October 22-24. Kremlin aide Yury Ushakov said on Wednesday that the list included 13 countries. The leaders of Belarus and Bolivia have also announced that their countries were on the list.
BRICS is an intergovernmental association that Brazil, Russia, India, and China created in 2006, and South Africa joined in 2010. The group had its second expansion this year, admitting Egypt, Ethiopia, Iran, the United Arab Emirates, and Saudi Arabia. The latter has reportedly not formalized its membership but has been taking part in BRICS meetings.