The Bloomberg Dollar Spot index has risen 1 percent this month, capping gains in crude and other commodities priced in the currency.
"In a market that's looking for direction, there's concern that any slowdown in the manufacturing sector would slow down demand".
Countering the rising USA crude output and inventories are voluntary supply cuts led by the Organization of the Petroleum Exporting Countries (OPEC) aimed at tightening the market and propping up prices.
Brent crude oil futures were last down 50 cents, or 0.8, at $62.19 a barrel by 1310 GMT.
An oil pumpjack and a tank with the corporate logo of state oil company PDVSA are seen in an oil facility in Lagunillas, Venezuela January 29, 2019. Both lines carry Canadian crude to the U.S.
"The price has yet to react in any noticeable way", Fritsch said of the sanctions.
Prices also dipped after data showed US crude inventories at Cushing, Oklahoma, the delivery point for USA crude futures, rose by more than 943,000 barrels in the week to February 1, traders said, citing data from market intelligence firm Genscape. The month was Brent crude's best month since April 2016. OPEC and associated partners agreed to cut 1.2 million barrels per day with OPEC being responsible for 800,000 barrels.
US sends aid to Colombia-Venezuela border amid Maduro rejection of help
This weekend he plans to oversee a deliberate provocation of the military by ordering in supplies of humanitarian aid. Guaido is trying to force Maduro from power, set up a transitional government and hold a new presidential poll.
Venezuela, which produced 1.15 million barrels per day in December, was forced to look for alternative clients for its crude oil following sanctions that prevent the state oil company PDVSA from exporting to the US unless the revenues are paid to opposition leader Juan Guaido.
WTI futures have declined from a peak for this year of $55.26 per barrel on Friday.
The Organization of the Petroleum Exporting Countries and its allies, including Russian Federation, agreed to production cuts effective from last month to beat back supply growth. For instance, Treasury officials rejected refiners' pleas to allow them to complete oil transactions that were contracted before sanctions were imposed without paying into a special account walled off from Maduro.
However, while OPEC is cutting output, the United States has expanded supply, with production most recently totaling 11.9 million bpd.
Also dampening market sentiment still were worries about weaker global economic growth and the US-China trade dispute. "China trade talks", said Gene McGillian, director of market research at Tradition Energy in Stamford, Connecticut.
US President Donald Trump last week said he would meet with Chinese President Xi Jinping, perhaps twice, in the coming weeks to try to seal a comprehensive trade deal with Beijing, but acknowledged it was not yet clear whether a deal could be reached.