Kaniva reported the meeting is to discuss government concerns over what have been called "violent attacks" on the royal family, posted on Facebook last month.
The comments prompted a government threat to ban access to the site.
It set up a panel to investigate the attacks which were believed to have been made by Tongans living in Australia.
The attorney general had said previously that police were considering bringing treason charges against the offenders.
She has told RNZ Pacific that "there's a couple of accounts with Tongan names that have actually shown pictures and comments which may amount to defamation or sedition or treason".