The global oil glut will last through 2016 as the strongest demand growth in five years and faltering supply fail to clear the surplus, according to the International Energy Agency.

Oil prices may fall further as the world remains “massively oversupplied,” before markets tighten in 2016 when output growth outside OPEC grinds to a halt, according to the International Energy Agency.

Oil declined in New York on April 30 after its biggest monthly advance since May 2009.

Oil declined from a one-week high in London and New York as Iraqi production advanced to a record, compounding a global supply surplus.