Mexico has joined Canada and Japan in asking to be included in the membership of the Trans-Pacific Partnership - the grouping of nine Pacific rim countries discussing a free trade deal.
The Trans-Pacific Partnership (TPP) was signed in 2005 by Brunei, Chile, New Zealand and Singapore.
Australia, Malaysia, Peru, the United States and Vietnam are now in talks to join it.
Canada and Mexico say they will start talks with the members of the Trans Pacific Partnership with a view to joining formal negotiations.
The announcement follows a similar expression of interest from Japan on Friday.
Canada's inclusion in the talks has been difficult until now because of restrictions it places on food imports including dairy products from New Zealand.
US President Barack Obama and Canada's Prime Minister Paul Harper discussed the country's desire to join the talks at the APEC summit in Honolulu on Sunday and Mr Obama says he highlighted the need for a commitment from Canada to tackle trade issues before it can be formally admitted.
Canadian Prime Minister Paul Harper said they had looked at the outline of the criteria set by the TPP and "they are all criteria that Canada can easily meet".
The BBC points out that President Obama has been pushing the region to open up its borders, calling US engagement in the Asia Pacific region "absolutely critical" to America's prosperity.
Mr Obama has indicated he wants the TPP talks to lead to a bigger deal covering all 21 APEC economies.
However, China's senior APEC official at the summit, Pang Sen questioned Mr Obama's assumptions about the TPP.
Mr Pang said other trade talks including China but not the US should also be considered as a starting point for a trade area covering Asia and the Pacific.
New Zealand's Trade Minister Tim Groser says this year's APEC summit has confirmed TPP is ahead of those competing talks.