Escalating trade tensions are threatening to derail a global upswing that is already losing momentum amid weaker than expected growth in Europe and Japan, warns the International Monetary Fund.

The IMF kept its global forecast unchanged Monday in the latest update to its Global Economic Outlook, even though financial markets seem complacent to the mounting risks. The world economy will grow 3.9 percent this year and next, the Washington-based fund said. The pace this year would be the fastest since 2011.

But cracks are forming in the growth picture. The global expansion is becoming less balanced, with growth sputtering in the eurozone and Japan.