He said others could hold different views, but he did not want to overstate the significance of New Zealand's decision tosoften travel sanctions and restore full diplomatic links with Fiji.
"There's always a chance Bainimarama won't go ahead with those elections - that's been the position in the past - so we'll take it one step at a time."
Other Pacific leaders had similar views. Cook Islands Prime Minister Henry Puna said he did not believe the suspension should be lifted. "It is important that the integrity of the forum leaders' position is maintained. But there may be other levels of engagement we can look at."
He said there was a strong feeling that Fiji should be involved in the meetings of the Pacific group at the forum.
Samoan Prime Minister Tuilaepa Aiono Sailele Malielegaoi - who has been oneof Commodore Bainimarama's strongest critics - said he also welcomed the progress Fiji had made, but believed lifting its suspension from the forum was "premature".
"Whether [elections] will actually take place is a secret to all of us."
Tuilaepa said support had to be given for elections so that Fiji could not use a lack of resources as an excuse to back away from its commitment.
University of Auckland Pacific studies lecturer Steven Ratuva said some leaders were likely to push for Fiji to be invited back next year but Australia could be reluctant.
He did not believe Fiji could backtrack on its promise of full elections in 2014, saying the interim Government was now in a position of "elections or doom".
He believed the recent softening in the stance of Australia and New Zealand was partly due to pressure from the United States.
Dr Ratuva said the Americans were concerned China was taking advantage of the vacuum left by Australia and New Zealand in Fiji to get a firm toehold in the region.
China had given aid and loans to many Pacific nations, but particularly intensively in Fiji, which was criticially important because it was a transport and commercial hub.
The European Union's representative at the leaders' gathering, David O'Sullivan, said the EU would again take its lead from the forum.
It had frozen major sugar subsidies for Fiji since the December 2006 coup and he did not believe they would be restored soon.
Mr Key said he expected the Pacific meeting to cover other topics including the management of fisheries, which was a major issue.