OPEC said the oil market outlook in the second half of 2018 is highly uncertain even though the producer group’s figures show a global glut has ended, suggesting talks next week on relaxing a supply cut deal won’t be straightforward.

other OPEC states and non-OPEC allies aim to stick to a global pact on cutting oil supplies until the end of 2018 but are ready to make gradual adjustments to offset any supply shortage, a Gulf source familiar with Saudi thinking said.