The world's debt load has ballooned to a record $US164 trillion ($211 trillion), a trend that could make it harder for countries to respond to the next recession and pay off debts if financing conditions tighten, the International Monetary Fund said.

The record debt number overshadowed some positive signs for the global economy. Credit:Edwina Pickles

Global public and private debt swelled to 225 per cent of global gross domestic product in 2016, the last year for which the IMF provided figures, the fund said Wednesday in its semi-annual Fiscal Monitor report. The previous peak was in 2009, according to the Washington-based fund.

"One hundred and sixty-four trillion is a huge number," Vitor Gaspar, head of the IMF's fiscal affairs department, said in an interview. "

The global debt burden clouded the IMF's otherwise upbeat outlook of the world economy, which is in its strongest upswing since 2011. The fund on Tuesday forecast expansion of 3.9 percent in 2018 and 2019, while saying in subsequent years the global economy could be impacted by tighter monetary policy and the fading effects of US fiscal stimulus.