NUSA DUA, Indonesia (AP) — World Bank President Jim Yong Kim says the trade tensions escalating between the U.S. and China could undo global progress in helping end extreme poverty.

Speaking at the outset Thursday of the annual meeting of the World Bank and International Monetary Fund on the island of Bali in Indonesia, joined the IMF’s chief in warning of the risks to world growth and economic development from threats to world trade.

The U.S. has imposed tariffs on tens of millions of dollars of Chinese exports and Beijing has responded with similar retaliatory taxes on imports of U.S. goods.

Kim said the most extreme measures, if imposed would cause a “clear slowdown.”

He said that without free trade, there would be no hope of helping millions of people escape dire poverty.