The Commonwealth Secretariat says it has been asked by the Nauru government to give technical assistance ahead of this year's election.
But it said it had not been formally asked to send observers to Nauru, where the international agency last monitored voting 12 years ago.
Earlier this week, two former presidents called on the Commonwealth and the Pacific Islands Forum to step in to monitor what they considered controversial changes to the electoral process.
The Nauru election is due mid-year but Sprent Dabwido and Marcus Stephen wanted observers there as soon as possible.
In a statement the Commonwealth said it was committed to supporting free and fair elections in its member countries in accordance with the Commonwealth Charter.
It said technical assistance would be provided in the coming weeks to help deliver a high quality election process.
But the agency said it would only observe an election when invited to do so by the national authorities and it had not yet been invited by Nauru.
On the government website, Nauru's president, Baron Waqa, said election observers were welcome at any time.