Instead, he has told the Fiji Sun newspaper that he will be going to the Queen's birthday celebrations in London.
The MSG summit in Port Vila is to revisit the appointment of Fiji's Amena Yauvoli as the new director general of the MSG secretariat.
Mr Yauvoli's selection was announced at the start of the month by Fiji's Foreign Minister Ratu Inoke Kubuabola and later confirmed by the MSG chairman, Solomon Islands prime minister Manasseh Sogavare.
But the announcement was not welcomed by Vanuatu which refuses to accept it, while Papua New Guinea says no proper process was followed.
The summit is also expected to deal with a push by Vanuatu to remove Indonesia from the MSG after Jakarta admitted its police uses torture.