Celtic Rugby confirmed on Wednesday that the association had held positive talks with the South African Rugby Union regarding the inclusion of two Super Rugby teams into Pro12 next season.
Celtic Rugby, which represents Irish, Welsh, Scottish and Italian rugby union, wants to expand the current 12-team formula.
Super Rugby is set to cut three franchises, including two South African sides, from the 2018 season with the Cheetahs and Southern Kings already announced by the SARU as the two teams which will lose their licences for 2018.
"Advanced and positive discussions are taking place with the South African Rugby Union regarding the introduction of two teams into an expanded Pro 12 Championship," a Celtic Rugby spokesman said.
"Given the proximity of the 2017/18 season start, a final decision on this potential expansion will be confirmed as soon as practical."
The Celtic League is regarded as weaker than its rival northern hemisphere leagues, with English Premiership and French Top 14 clubs carrying more financial clout and performing more consistently on the European stage in recent years.
Italian sides Treviso and Zebre, who tend to occupy the bottom two positions every season, are regarded as the Celtic League's weakness, while the introduction of two South African sides would likely provide greater competition and bring in much-needed revenue in an attempt to bridge the gap to wealthier leagues.
SANZAAR are yet to officially confirm which franchises will lose their status.