Investing.com - Oil edged lower Tuesday as the focus turned to U.S. stockpile data.
Brent crude was off 27 cents, or 0.48%, at $55.45 at 08:00 ET. U.S. crude shed 26 cents, or 0.49%, to $52.75.
The market was underpinned by fresh sanctions imposed on Iran by the U.S. after ballistic missile testing by Tehran.
Increased U.S. drilling could derail the impact of agreed cuts by other major producers.
OPEC and non-OPEC producers have agreed to cut production by 1.8 million barrels a day in the first half of this year.
American Petroleum Institute U.S. inventory figures are due out later in the session.
These will be followed Wednesday by official Energy Information Administration inventories.
U.S. crude stocks are forecast to have increased by 2.38 million barrels in the latest reporting week.