Oil edged up after Saudi Arabia and Russia reaffirmed they will stick with oil supply curbs of more than 1 million barrels a day through the end of the year.
Oil rose to near $73 as traders evaluated a warning from Saudi Energy Minister Prince Abdulaziz bin Salman to short-sellers, offsetting a lack of tangible progress in US debt-limit talks.
Oil rose above $81 a barrel, buoyed by general risk-on sentiment, as the first of a spate of supply-and-demand projections scheduled this week forecast a modest rise in US production.
Oil rose after a government report showed the US is exporting a record number of crude and refined products as the market waits to learn whether nuclear negotiations will clear a path for Iran to sell more oil.