Oil prices fell after Greece became the first developed nation to default on International Monetary Fund (IMF) debt, while crude output from both the US and the Organization of Petroleum Exporting Countries (Opec) surged.
WTI crude for delivery in August fell 1.19% at $58.76 (£37.36, €52.55) per barrel as at 9.23 pm ET, while Brent crude was trading down 0.83% at $63.06.
Greece earlier defaulted on its €1.6bn IMF loan – the largest missed payment in the history of the IMF.
"I confirm that the SDR 1.2 billion repayment (about €1.5bn) due by Greece to the IMF today has not been received. We have informed our Executive Board that Greece is now in arrears and can only receive IMF financing once the arrears are cleared," Gerry Rice, director of communications at the IMF, said in a statement.
"I can also confirm that the IMF received a request today from the Greek authorities for an extension of Greece's repayment obligation that fell due today, which will go to the IMF's Executive Board in due course."
Following the default announcement, the euro was trading down 0.07% against the US dollar at 1.1139, while the pound fell 0.10% at 1.5696.
The dollar strength generally increases the oil import bill of many countries as the commodity is priced in the US currency.
In addition, higher estimates of output from both the Opec and the US are weighing on prices.
"Iraqi crude production climbed to a record level this month, with Opec crude oil output estimated to have reached 32.1 million barrels per day against a target of 30 million barrels per day," analysts at ANZ bank said in a note.
A deal between Iran and world powers over the country's nuclear programme is expected to significantly increase oil supply to the global market. Iran and six world powers extended the deadline for nuclear talks until 7 July.
The US Energy Information Administration earlier said crude production in the country increased by 9,000 barrels per day to 9.701 million barrels per day in April, the highest level since May 1971.