More needs to be done to promote global economic growth, and any additional U.S. deficit reduction must be restrained, the International Monetary Fund's Christine Lagarde told CNBC's "Closing Bell" on Wednesday.
"At the moment government with their fiscal policies have limited space, and yet growth has to pick up," the IMF chief said. "So who bears the burden—central bankers with monetary policies that are unconventional."
Global central banks are doing what they can to encourage growth and to ensure that credit flows into the real economy to jump-start investment, Lagarde said.
She also warned that "massive, brutal, up-front additional fiscal consolidation" in the U.S. would hamper growth, adding that it has undergone fiscal consolidation of about 5 percent since 2009.
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Instead, the nation needs to come up with a medium-term strategy to fix its fiscal problems. "The world needs to know the U.S. has a plan to reduce its high debt and to keep under control its deficit and reduce it," she said.
Lagarde also sees little risk that massive central bank liquidity will trigger inflation.
"The risk traditionally would be accommodative monetary policy, massive liquidity, risk of inflation picking up," she said. "There is probably less of that."
While it's for central bankers to decide how they're going to go about exiting this unconventional monetary policy, Lagarde said, "the path out of it should be gradual, it should be thought through and it should be adequately communicated."