Worldwide benchmark Brent crude oil futures were at $83.25 per barrel at 0115 GMT, down 91 cents, or 1.1 percent, from their last close.
Reuters separately said that India will buy 9 million barrels of Iranian oil in November, indicating that the world's third biggest oil importer would continue to buy crude from the Islamic Republic despite the United States sanctions.
U.S. West Texas Intermediate (WTI) crude CLc1 futures rose 35 cents to $74.68 a barrel by 1:07 p.m. EDT (1707 GMT).
Oil dropped to around $83 a barrel on Monday, pressured by expectations that some Iranian oil exports will keep flowing after the US reimposes sanctions, easing a strain on supplies.
The market is expected to remain volatile till it gets clarity on what will be the ultimate drop in Iranian exports and to what extent other oil producers will fill the gap.
While Goldman Sachs Group Inc is not that bullish, the Wall Street bank sees a risk of oil holding above US$80 toward the end of the year.More news: Manchester United 3 Newcastle United 2: Sanchez completes stunning turnaround
"Iran has been off-and-on taking rupee payments for oil it sells".
The currency is also set to face an onslaught from last month's decision by the US Federal Reserve to increase the Federal Funds Rate to a range of up to 2.25 per cent from the 1.75 per cent set in June 2018.
For weeks, crude oil has been underpinned and driven higher by US sanctions set to target Iran's crude oil exports during the first week in November, and the Trump administration has been leaning on governments and global companies to cut their imports to zero.
Secretary of State Mike Pompeo announced on Wednesday the termination of the USA and Iran's 1955 Treaty of Amity, Economic Relations, and Consular Rights following Iran's use of the document as justification to take the U.S.to the United Nations' International Court of Justice (ICJ) over sanctions imposed by the Trump administration. Saudi Arabia at present produces 10.7 million barrels per day. The kingdom is willing to tap all of its spare capacity, Mr Al-Falih said.
Russian Federation has "benefited tremendously" from its co-operation with OPEC over recent months, the head of Russia's investment fund said, but rising oil prices are quickly becoming a concern.
Rising US gasoline prices ahead of midterm elections have caused President Donald Trump to ratchet up pressure on Saudi Arabia to increase production. "It now appears that only China and Turkey may be willing to risk US retaliation by transacting with Iran". This means that any supply disruption can send prices soaring again as well as Asia's strong demand.