Oil ticked up on Thursday, with trading volumes thinning ahead of the Easter holidays, fresh U.S. sanctions targeting Iranian oil exports have sparked renewed concerns over global supply.

Brent crude added 1.3% to $66.69 per barrel, while US WTI advanced by 1.5% to $63.39 per barrel.

The two benchmarks closed 2% higher on Wednesday, hitting their highest since April 3 and heading for their first weekly gain in three. Thursday marks the final settlement before the Easter break.

New U.S. sanctions on Iranian oil and firm remarks from the Treasury are fueling supply concerns and boosting crude prices, said UBS analyst Giovanni Staunovo.

Sanctions announced Wednesday by the Trump administration, targeting entities including a small China-based "teapot" refinery, increase pressure on Tehran amid ongoing nuclear talks. "Teapot" refers to small, independent oil refiners.

OPEC said Wednesday it received revised plans from Iraq, Kazakhstan, and others to deepen output cuts and offset previous overproduction.

U.S. gasoline and distillate stocks declined last week, buoying prices on Thursday, according to the Energy Information Administration.

OPEC, the IEA, and major banks like Goldman Sachs and JPMorgan lowered their oil price and demand forecasts this week, citing global trade disruptions from U.S. tariffs and retaliatory measures.