OPEC on Wednesday trimmed its forecast for growth in oil supply from the United States and other producers outside the wider OPEC+ group this year and said it expected lower capital spending following a decline in oil prices.

World shares are mostly lower while oil prices fell more than $2 as traders bet on a possible U.S.-Iran nuclear deal. U.S. futures also slipped after a mixed day on Wall Street. China moved to reverse some of its “non-tariff” measures against the U.

Oil prices dropped Monday, as the Organization of the Petroleum Exporting Countries and its allies agreed to boost output again in June, raising concerns about a potential oversupply at a time when markets are grappling with the uncertainties of a global trade war.