Nauru Olympic Committee President Marcus Stephen has said not competing in this year's Micronesian Games is a "big disappointment".
The multi-sport event began today in Yap with the Opening Ceremony but Nauru have not made the journey due to financial issues.
They could not afford to charter a flight to Yap, or even share the costs with the team from Kiribati.
Stephen, a three-time Olympic weightlifter and a former World Championship silver medallist, said a main factor was the money spent competing at this year's Commonwealth Games in Gold Coast in Australia.
"Our Government, even though very supportive, saw that it was not feasible to spend this kind of money," Stephen said to the Pacific Daily News.
"For future Games, if hosted up north, we hope that some consideration and concession can be given to Nauru and Kiribati to assist us.
"I would like to take the opportunity to wish everyone success and the best of luck for the Games."
Held every four years, the multi-sport event welcomes teams from the Micronesia region.
Yap are one of four states from the Federated States of Micronesia which takes part - alongside Chuuk, Pohnpei and Kosrae.
Teams will also travel from Marshall Islands, Palau, Kiribati, Northern Mariana Islands and Guam.
The sports on the programme include men's baseball, basketball, volleyball, beach volleyball, football, athletics, table tennis and weightlifting.
Wrestling, va'a canoe and open water swimming also feature, alongside the traditional Pacific island sports of spearfishing and the "Micro All Around".
The All Around contains a swim/dive/run event, spear throwing, coconut tree climbing and coconut husking and grating.
After today's Opening Ceremony, sport will now continue until July 27.