Around 260 delegates are expected at next week's Pacific Islands Forum leaders meeting in Apia.
This number includes those attending the post forum dialogue while up to 80 media are also expected.
The chair of the organising committee, Mose Sua, who is the Chief executive of Samoa's Ministry of Foreign Affairs, says late confirmations are posing some difficulties for them in fitting people into the accommodation available.
"Accommodation is always a problem because advice is still coming in of additions to delegations and media are also sending in more people, so it is always difficult to plan for those kinds of bookings with the hotels. They are also trying to hold off on their own arrangements for usual visitors."