Russia's top financial diplomat said the Group of 20 should focus on making new commitments to curb borrowing, and not rush to judge Japan's bid to reflate its economy when policy makers meet this month.
Moscow hosts finance ministers and central bankers on Feb. 15-16 as controversy over "currency wars" has opened a rift between indebted rich nations and faster-growing exporters who fear a wave of competitive devaluations.
Russia is the first big emerging economy to assume the annual presidency of the G20, which became the world's top crisis management forum after the 2008 crash.
One of its central bankers has accused Tokyo of "protectionist monetary policy".
But its finance 'sherpa', Deputy Finance Minister Sergei Storchak, told Reuters the currency debate should be kept within sensible bounds.
"It cannot go without a reaction, but the reaction must be proper, so as not to send signals to the market that are disproportionate to the problem," Storchak said in an interview on Thursday night.
Spurring widespread criticism, the Bank of Japan announced last month that it would buy unlimited amounts of assets and double its inflation target to 2 percent in a bid to escape two decades of deflationary stagnation.
"Japan is an open economy and I think that one should think a lot - a lot - before accusing it of a competitive devaluation," Storchak said, echoing a conciliatory line taken by Russia's top summit sherpa, Ksenia Yudayeva.
Storchak added that the unorthodox monetary policies pursued in recent years, including in the United States and euro zone, showed how inadequate their growth models were in a post-crisis world.
"One country cannot live from imports, and another just from exports," he said.
The G20 accounts for 90 percent of the world economy and two-thirds of its population, making it the most practical and representative forum to conduct the global policy debate.
Yet although countries led by China and Russia own trillions of dollars in reserves, mainly invested in the sovereign debt of developed nations, they have a relatively small voice at the world's lender of last resort, the International Monetary Fund.
The IMF has missed a self-imposed deadline to agree a new formula for allocating voting power among its members, however.
Storchak played down chances of a breakthrough.
"It would be reasonable to expect that in the next six months, there should be more exploitation of the G20's potential to find solutions on quotas," he said. "We need to hook up a G20 mechanism here."