President Bush congratulated Mr Key on his election win, and President Hu invited him to visit China.
A spokesman for Mr Key told NZPA the meetings during the leaders' retreat were brief and it was possible more substantial discussions would take place before the summit ends late tomorrow.
Mr Key is alongside prime ministers and presidents from 20 countries at the Asia-Pacific Economic Co-operation summit, where discussions are taking place against the backdrop of the international financial crisis and deteriorating economic conditions.
Those issues are central to Mr Key's concerns about the impact a global recession will have on New Zealand's economy, and he formed his new government quickly so he could attend the summit.
So far he has held formal bilateral meetings with Australian Prime Minister Kevin Rudd, Chilean President Michelle Bachelet, OECD Secretary-General Angel Gurria and Singapore's Prime Minister Lee Hsien Loong.
In a speech yesterday to Apec's Business Advisory Council, also known as the CEO's summit, Mr Key pulled no punches when he blamed banks and other financial institutions for plunging the world into crisis.
"We have seen an expansion of credit and leverage at levels that were so unprecedented and arguably so uncontrolled that they now threaten the very stability of the world's banking system," he said.
"There is no precedent for such a large and widespread leverage boom as we have experienced in recent years and hence little way of knowing how far the unwinding process may have to run." Mr Key said in many cases there had been a "recklessly complacent attitude to risk" and credit had become out of proportion to real economies.
But his main point was that free trade -- Apec's founding principle -- was the most important way to get out of the crisis.
"Now is most definitely not the time for any individual country to allow their worsening domestic economy to lead to a retreat from global trade and engagement," he said.
Mr Key said if the World Trade Organisation's current round of negotiations to liberalise trade did not reach a successful conclusion, that would represent "nothing short of political failure".
President Bush has made the same plea, saying in a speech that free markets and trade was the most important way to achieve a "rebound" from falling productivity and increasing unemployment.
Apec member countries account for half the world's trade and nearly 60 percent of its gross domestic product.
The summit brings together the leaders of Australia, Brunei, Canada, Chile, China, Indonesia, Japan, Hong Kong, South Korea, Malaysia, Mexico, New Zealand, Papua New Guinea, Peru, the Philippines, Russia, Singapore, Taiwan, Thailand, the United States and Vietnam.
It is expected to issue a communique late tomorrow emphasising the need for a co-ordinated approach to solving the financial and economic crisis.
From Lima, Mr Key is going to London where he will meet the Queen, Prime Minister Gordon Brown and other political leaders before coming home.
