Oil markets jumped on Monday on concerns over potential renewed US sanctions against Iran as well as conflict in Iraq.
Brent crude futures LCOc1, the international benchmark for oil prices, were at $57.85 at 0356 GMT, up 68 cents, or 1.2 per cent, from the previous close, reports Reuters.
Traders said that worries over renewed US sanctions against Iran were pushing up prices.
US President Donald Trump struck a blow against the 2015 Iran nuclear deal on Friday, defying both US allies and adversaries by refusing to formally certify that Tehran is complying with the accord even though international inspectors say it is.
Under US law, the president must certify every 90 days to Congress that Iran is complying with the deal. The US Congress will now have 60 days to decide whether to reimpose economic sanctions on Tehran that were lifted under the pact.
During the previous round of sanctions against Iran, some 1 million barrels per day (bpd) of crude oil supplies were cut off global markets.
While analysts said they did not expect renewed sanctions to have such a big impact again, especially as the United States would likely act alone, they did warn that such a move would be disruptive.
There were also concerns about the stability of Iraq, the second biggest oil producer within the Organisation of the Petroleum Exporting Countries (OPEC) behind Saudi Arabia.
Iraqi forces on Sunday began moving towards oil fields and an important air base held by Kurdish forces near the oil-rich city of Kirkuk, Iraqi and Kurdish officials said.
US West Texas Intermediate (WTI) crude futures CLc1 were trading at $51.89 per barrel, up 44 cents, or 0.9 per cent.