The leaders are endorsing a declaration made at last weekend's summit in Washington, saying they won't raise new trade barriers over the next year.
They are also pledging to reach agreement next month on the outlines of a World Trade Organization pact that collapsed in July after seven years of negotiations.
A spokesman for the Japanese government said Saturday that concern over the global financial crisis revived willingness to push forward on the so-called Doha round of trade talks.
Addressing the Asia-Pacific Economic Cooperation (APEC) summit in Lima on Saturday, South Korean President Lee Myung-bak said the world must resist protectionist measures even if companies will keep going bankrupt and countless jobs will be lost.
U.S. President George W. Bush, attending his final global summit at a time of severe financial crisis, also said such measures would "stifle innovation and strangle growth."
He urged other countries on Saturday to spurn calls to erect protectionist trade barriers and keep pushing to liberalize trade, and to not repeat mistakes that turned a similar calamity seven decades ago into the Great Depression.
"One of the enduring lessons of the Great Depression is that global protectionism is a path to global economic ruin," Mr. Bush said in comments to business executives of Pacific Rim countries.
Mr. Bush said that because the economic problems are so widespread, all nations - both developed and developing - must work together to find solutions. He urged them to resist the "temptation to overcorrect" to fix the fiscal crisis. Mr. Bush has argued against over-regulating financial markets.
"Recovering from the financial crisis is going to take time, but we'll recover and so begin a new era of economic prosperity," he declared.
Mr. Bush was hoping to use his final APEC summit to get endorsement of a sweeping action plan to attack the global financial crisis that was drafted last week in Washington at a meeting of the Group of 20 nations, which include the world's richest economies plus major developing nations such as China, Brazil, India and Russia. Nine of the countries at the G-20 meeting are also members of APEC.
Mr. Bush said the APEC meeting could send a message that "we refuse to accept protectionism in the 21st century."
The APEC leaders were expected to commit to wrapping up the broad outlines of a free-trade agreement by the end of December.
However, some fear leaders will be unwilling to hold serious talks until U.S. President-elect Barack Obama takes office in January. He did not send representatives to Lima.
Free Trade Pushed
The two-day summit was taking place following another bad week for financial markets as investors became more fearful about the prospects of a deepening global recession.
Mr. Bush said that when he took office, the United States had free-trade agreements in effect with only three countries. Now it has such pacts in force with 14 nations. To hearty applause, he called it "extremely disappointing" that the U.S. Congress adjourned without passing pending deals with Colombia, South Korea and Panama.
Mr. Bush also said it was important for nations to push ahead to complete the global free-trade talks known as the Doha Round.
These discussions, which began seven years, ago have been stalled by disputes between rich and poor nations over farm trade and barriers to manufactured goods.
In addition to addressing the economic crisis, Mr. Bush used his discussions in Lima to provide renewed impetus to an effort to rid North Korea of its nuclear weapons. North Korea has balked at allowing inspectors to take samples from its main nuclear complex.
Mr. Bush hopes to use his discussions with the leaders of Japan, South Korea and Russia to lock in an early December date when all six parties, including North Korea, will meet in China. The goal would be to get agreement on the verification of North Korea's nuclear declaration and disabling of its nuclear facilities.
At a meeting with Canadian Prime Minister Stephen Harper, Mr. Bush joked about his "forced retirement" on Jan. 20 when Barack Obama replaces him.
Harper: Bad Government Policies Caused The Great Depression
Canadian Prime Minister Stephen Harper said the current economic crisis is potentially as dangerous as anything the world has seen since 1929.
And he said the world must learn the lessons from the Great Depression, which he says was not caused by a stock market collapse but by bad policies from governments, so as to avoid a repeat of history.
He said policy makers erred in allowing their banking sector to contract, deflation to take hold, attempted to balance government budgets when fiscal stimulus was needed, and closed doors to trade in an effort to protect domestic jobs.
Those are mistakes Canada would not make, he said in an address to the APEC summit on Saturday.
Russian President Dmitry Medvedev was also among the leaders who arrived in Lima on Saturday morning to attend APEC.
Local newspapers reflected on the likelihood that the global financial crisis would dominate discussions at the summit.
On the streets of Lima on Saturday morning, massive security was deployed around the hotels hosting the different delegations.
Authorities in Lima declared Thursday and Friday public holidays in the capital in order to reduce traffic and ensure better security measures for the summit. Many Lima residents took advantage of the four-day-long weekend to leave the capital.
The protesters, who were called to action by one of Peru's main trade unions, also burned a rat effigy intended to represent Peruvian President Alan Garcia, among other political figures.
Union leaders blamed a poor turn out at the protest on a lack of public transport in the capital, because of the public holiday.