President Bush warned of a long road to financial recovery after the second day of an emergency summit with G20 leaders.
World leaders at the Group of 20 summit, including major developing world economies such as China, Russia, India and Brazil, have agreed to coordinate and modernize their financial systems to stem the global economic crisis.
The group laid out guidelines for financial reform, including enhancing regulation and strengthening transparency.
The G20 vowed "to take whatever further actions are necessary to stabilize the financial system," while reaffirming a commitment to free trade.
The outgoing Bush said that the leaders had made great strides at the session toward "adapting our financial systems to the realities of the 21st century." Bush said the leaders will also take "a fresh look at rules that govern market manipulation and fraud."
The leaders, who represent 90 percent of the world's economy and 75 percent of the global population, agreed to reform international financial institutions such as the World Bank and the International Monetary Fund.
Bush said the United States could have fallen into a depression worse than the Great Depression without the steps taken by his administration, including the $700 billion financial bailout.
"Whatever we do, whatever reforms are recommended, we need to be guided by this simple fact: that the best way to solve our problems and solve the people's problems is for there to be economic growth. And the surest path to that growth is free-market capitalism."
"For those who have followed my career, I'm a free-market person," Bush said.
The lame-duck President also said he is working closely with President-elect Barack Obama's transition team to develop a sound financial strategy.
"We will work tirelessly to make sure the transition between my administration and his administration is seamless," he said.
The G20 plans to meet again after Jan. 20, when Obama takes office.