Oil prices were dragged sharply lower on Friday by weak U.S. fuel demand, fears of a second wave of coronavirus cases in South Korea, and a worsening in U.S.- China relations, but were still on track for a hefty monthly gain.
July Brent crude fell 72 cents, or 2%, to $34.57 a barrel by 1203 GMT and the more active August contract also lost 72 cents, or 2%, to $35.31. U.S. West Texas Intermediate (WTI) crude was down 83 cents, or 2.5%, at $32.88.
Both contracts were on course for their first weekly loss after four consecutive weeks of gains that leave them set for the biggest monthly advance in years thanks to production cuts and optimism over Chinese-led demand recovery, analysts said.
WTI is on track for a record monthly gain of 75% in May, with Brent set for a 37% increase that would represent its strongest monthly rise since March 1999.
"The global reaction to China's move to propose new security laws for Hong Kong continues to increase, while there's a score of new COVID-19 cases in South Korea," said Rystad Energy's head of oil markets, Bjornar Tonhaugend.
U.S. President Donald Trump is due to announce his response to the situation in Hong Kong later on Friday.
Thursday's data from the Energy Information Administration showed that U.S. crude oil and distillate inventories rose sharply last week. Fuel demand remained slack even as various states lifted travel restrictions they had imposed to curb the coronavirus pandemic, analysts said.
Looking ahead, traders will be focusing on the outcome of talks on output cuts between the Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia, a group known as OPEC+, in the second week of June.
Saudi Arabia and some OPEC members are considering extending record production cuts of 9.7 million barrels per day beyond June, but have yet to win support from Russia.
(Additional reporting by Florence Tan in Singapore Editing by David Goodman)