In a joint communique issued following the meeting, finance officials pledged not to target exchange rates or devalue currencies to make them more competitive.
Russian Finance Minister Anton Siluanov said all the G20 nations agreed to deliver strong economic growth rather than manipulate the markets.
But he warned if too many countries tried to weaken their currencies for economic gain, the fragile global recovery could be derailed.
"If the government or central bank interferes in this pricing process accordingly, disproportions could occur and after short relief, disproportions would occur in any case."
Chief of International Monetary Fund Christine Lagarde urged the United States and Japan to come up with specific strategies to trigger economic growth that do not depend solely on monetary policy.
"There is a clear understanding on the part of both the U.S. authorities and the Japanese authorities present with us on the occasion of this meeting that the fiscal agenda is critical.
And what I mean by fiscal agenda is clearly the medium-term goal that has to be identified, that has to be supported broadly in those countries, and that needs to be specific and detailed enough in order to eliminate as much as possible the uncertainty that goes with a lack of an agenda."
The Japanese yen plunged recently against other major currencies following moves by Japan's new leaders to ease monetary policy and stimulate the economy.
Xiang Songzuo, chief economist at the Agricultural Bank of China, believes developed economies will not give up their loose monetary policies in the short term.
"The developed economies, whether it is the U.S., Britain or Japan, the possibility for them to withdraw the loose monetary policy is small because the trend of economic recovery for these nations is still uncertain and fragile. We have to be mentally prepared for the uncertainty and take action at any time."
Meanwhile, China cited the fact that the U.S. has pledged to implement the global banking regulatory standard Basel III in the coming months, while the European Union has submitted the bill for parliamentary approval.
Vice Finance Minister Zhu Guangyao said China welcomes the moves.
"Although the U.S. and EU delayed putting Basel III into practice, they have realized the importance of the standard and the responsibility they should assume in implementing it. Thus, the efficient implementation of the Basel rules will enrich the contents of the G20 accord and enhance the group's credibility."
The Basel III rules on bank capital adequacy aim to strengthen bank capital requirements and introduce new regulatory requirements on bank liquidity and capital adequacy ratios in response to the global financial crisis.
