Such a vital issue concerning Assam should have been raised by the Prime Minister during his talks with his Chinese counterpart, the Chief Minister said in a statement here.
"By not raising the serious issue and putting it on the back burner, the Prime Minister has done grave injustice to Assam and its people," he added.
Gogoi had earlier urged Modi to take up the issue of construction of dams over the Brahmaputra by China during his visit to the neighbouring country.