The President has previously alleged that neither country can join the organisation until Bosnia and Herzegovina changes its election laws.
In late April, he said NATO should “let them join”, but until western allies forced officials and Bosnia and Herzegovina to “change the election law in the next six months and give Croats their fundamental rights” Croatia’s Parliament “must not ratify anyone’s accession to NATO”.
He added: “For me, that’s a vital national interest of the Croatian state, nation and people, that BiH be a functioning state.”
The law in question allows Bosniaks to elect a Croatian member of state to the presidency.