Oil prices edged lower in early Asian trade on Tuesday, trimming the previous session’s gains as oversupply worries outweighed optimism over a possible U.S. government shutdown deal.

Brent crude fell 0.2% to $63.93 a barrel, while WTI slipped 0.2% to $60.00. Both had gained about 40 cents on Monday.

Analysts from Ritterbusch and Associates said rising OPEC production and slowing global demand are keeping the market under pressure despite broader optimism.

Meanwhile, U.S. sanctions on Russian oil majors Rosneft and Lukoil are disrupting global supply chains, with Lukoil declaring force majeure at its Iraqi oil field and Bulgaria moving to seize one of its refineries.

Oil stored on ships in Asian waters has also doubled recently as sanctions and weaker demand from China and India weigh on the market outlook.