Oil prices fell about 1 percent on Monday after nuclear talks between the United States and Iran progressed, reducing the concerns that the dispute will reduce supply from the major Middle Eastern producer.

Brent crude futures slipped 70 cents, or 1.03 percent, to US$67.26 a barrel at 0030 GMT after closing up 3.2 percent on Thursday. US West Texas Intermediate crude was at US$64 a barrel, down 68 cents, 1.05 percent, after settling up 3.54 percent in the previous session. Thursday was the last settlement day last week because of the Good Friday holiday.

The US and Iran agreed on Saturday to begin drawing up a framework for a potential nuclear deal, Iran's foreign minister said, after talks that a US official described as yielding "very good progress."

The progress on the nuclear discussions follows further sanctions by the US last week, ramping up pressure on Tehran amid the talks.

Concerns about tightening Iranian oil supply and hopes for a trade deal between the United States and the European Union, pushed both Brent and WTI up about 5 percent last week, their first weekly gain in three weeks.

Separately, Russia and Ukraine blamed each other on Sunday for breaking a one-day Easter ceasefire declared by President Vladimir Putin, with both sides accusing the other of hundreds of attacks and the Kremlin saying there was no order for a ceasefire extension. (Reuters)