Oil prices ticked up on Tuesday supported by rising geopolitical tensions as Russia and Ukraine ramped up the war and Iran was set to reject a U.S. nuclear deal proposal that would be key to easing sanctions on the major oil producer.

Crude had gained nearly 3% on Monday after the Organization of the Petroleum Exporting Countries and allies, known as OPEC+, kept its July output hike at 411,000 barrels per day, the same as earlier months and less than some in the market had feared.

Brent crude futures gained 43 cents, or 0.7%, to $65.06 a barrel by 0807 GMT. U.S. West Texas Intermediate crude was up 50 cents, or 0.8%, to $63.02.

"Risk premia have filtered back into the oil price following deep Ukraine strikes on Russia over the weekend," said analyst Harry Tchilinguirian of Onyx Capital Group.

"But more importantly for the barrel count, there is the to and fro between the U.S. and Iran regarding uranium enrichment."

Ukraine and Russia at the weekend ramped up the war with one of the biggest drone battles of their conflict, a Russian highway bridge blown up over a passenger train and an attack on nuclear-capable bombers deep in Siberia.

Iran, meanwhile, was poised to reject a U.S. proposal to end a decades-old nuclear dispute, an Iranian diplomat said on Monday, saying it fails to address Tehran's interests or soften Washington's stance on uranium enrichment.

Source: Reuters