Oil prices eased a touch but held near one-month highs on Friday as they headed for a third weekly gain on a tightening global supply outlook after the U.S. imposed tariffs against countries buying oil from Venezuela and placed curbs on Iranian oil trade.

Oil prices were mostly flat after rising earlier in the session on Thursday due to a fall in US inventories. According to the US Energy Information Administration, crude oil inventories in the country decreased by 3.

Companies planning a flagship offshore gas project between Venezuela and Trinidad and Tobago "have not slowed down" work, Trinidad Prime Minister Stuart Young said on Thursday, despite the United States increasing pressure on sanctioned Venezuela and uncertainty over the extension of a license for the project.

Interior Secretary Doug Burgum lauded millions in federal windfall from sales of oil and gas leases in Trump's first three months.

Oil prices edged higher on Thursday as traders assessed a tightening of crude supplies along with new U.S. tariffs and their expected effect on the world's economy.