The new head of the 189-nation International Monetary Fund says the world economy is in the grips of a "synchronized global slowdown" that will result in slower growth for 90% of the world this year.

IMF Managing Director Kristalina Georgieva said Tuesday that the updated IMF forecast to be released next week will show growth falling to its lowest point since the beginning of this decade.

She blamed much of the slowdown on rising trade conflicts which she said could mean a loss of around $700 billion in output by the end of next year — 0.8% of world GDP.

"Everyone loses in a trade war," she says in remarks urging all nations to pull back from the escalating trade wars such as the US-China trade battle.