主要 しゅよう こく首脳 しゅのう会議 かいぎであれば
shuyō koku shunō kaigideareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 主要国首脳会議

1. If it is the summit of major countries; If the summit of major countries were to be held

Ba Conditional