Oil fell by more than $1 a barrel on Monday to settle at over four-year lows as an OPEC+ decision to expedite its output hikes stoked fears about rising global supply at a time when the demand outlook is uncertain.

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.

Prices plunged after OPEC and its allies agreed to increase output again, despite weak prices and an uncertain demand outlook.