"Our view right now is that we would like to focus on deepening reform within APEC before we look at expanding membership at this time," Patricia Haslach, U.S. senior official for APEC, told reporters.
APEC leaders, including U.S. President George W. Bush, Russian President Vladimir Putin, Chinese President Hu Jintao and Japanese Prime Minister Shinzo Abe, are expected to discuss the membership issue among wide ranging topics at the forum's summit in Sydney on September 7-9.
Haslach noted that about a dozen countries were lined up for membership of APEC, the only forum that covers both sides of the Pacific Ocean. She did not name them.
Russia, Peru and Vietnam were the last to be included in APEC in 1997 before its leaders slammed the door for a decade on others in the membership line.
Potential candidates include failed applicants from 1997 - India, Colombia, Ecuador, Macao, Mongolia, Pakistan, Panama and Sri Lanka - as well as Association of Southeast Asian Nations states that have not yet joined APEC: Cambodia, Laos and Myanmar.
"I expect that they (leaders) will have the discussions but it has to be consensus whether to lift the moratorium," Haslach said.
Summit host Australia's APEC ambassador David Spencer had said in January that he would carry out individual consultations with senior officials to find out their views "because clearly this is a politically sensitive issue."
"Rather than have a broad open decision I think it is something that can be dealt with through quiet diplomacy for the time being," he said then.
But Haslach said Thursday she did not think that consensus had been reached on lifting the moratorium "at this point."
"Whether that can be achieved at the leaders (meeting), I wouldn't want to again speculate what the outcome would be of their discussions," she said.
Haslach also said that the leaders were expected to produce a "stand-alone statement" on the hot issue of addressing climate change, as well as study a report on regional economic integration.
The report may contain recommendations to help realize APEC's long term goal of a Free Trade Area of the Asia-Pacific.
"We are hoping that the leaders come out with some concrete recommendation for us - the senior officials - to carry forward" initiatives to expand on the plan next year, Haslach said.
APEC's current members are Australia, Brunei, Canada, Chile, China, Hong Kong, Indonesia, Japan, Malaysia, Mexico, New Zealand, Papua New Guinea, Peru, the Philippines, Russia, Singapore, South Korea, Taiwan, Thailand, the United States and Vietnam.
It is also the only group which brings together - every year - leaders from economies representing about half of global trade and 60 percent of global gross domestic product.
The 17-year-old APEC operates by consensus, meaning that the approval of each member is needed to reach a decision.
