NEW YORK: Oil prices fell 3% on Friday after US President Donald Trump tested positive for Covid-19, roiling risky assets, and as rising global crude output threatens to overwhelm the market's weak recovery.

Benchmark Brent and US crude were both headed for a second straight week of losses. The uncertainty surrounding the US president's health added to a series of jitters, including a lacklustre US unemployment report and increased supply from major world oil producers.

"It's been a rough week - and now the president's diagnosis sends a shudder through markets," said John Kilduff, partner at Again Capital in New York. "The Covid-19 pandemic has weighed more on the oil market than any other asset class. This is a worst-case scenario for the oil market."

Brent crude was down $1.12, or 2.7%, at $39.81 a barrel by 11:32 a.m. EDT (1532 GMT), after earlier touching a session low of $38.79 a barrel. US oil was down $1.04, or 2.7%, at $37.67 a barrel. US and Brent crude are heading for drops of around 6% and 5% respectively this week in a second consecutive week of declines.

The US labour market recovery slowed in September, as non-farm payrolls increased by 661,000 jobs last month after advancing 1.49 million in August, the US Labour Department said.

Crude supplies from the Organization of the Petroleum Exporting Countries (OPEC) rose in September by 160,000 barrels per day (bpd) from a month earlier, a Reuters survey showed. The rise was mainly the result of increased supplies from Libya and Iran - OPEC members that are exempt from a supply pact between OPEC and allies led by Russia, a group known as OPEC+.