U.S. oil price continued to drop Tuesday as investors awaited developments in the Greek debt crisis.

The first Eurogroup meeting on the Greek debt deal after Sunday 's referendum in Greece ended fruitless Tuesday, with lenders saying that their expectation for new Greek proposals fell, but Athens denied and insisted that they had in fact presented proposals.

The Greek people on Sunday gave an overwhelming "No" in the referendum on a rescue package from creditors, dramatically increasing the chance for the country to crash out of the Eurozone.

U.S. Energy Information Administration (EIA) will publish its report on last week's crude data Wednesday. Traders expected to see more information about U.S. crude inventories from that report.

Brent crude edged up as the Iran nuclear talks were extended. The negotiation between world powers and oil producer Iran to curb the latter's nuclear ambitions dragged into final days.

The West Texas Intermediate for August delivery moved down 20 cents to settle at 52.33 U.S. dollars a barrel on the New York Mercantile Exchange, while Brent crude for August delivery increased 31 cents to close at 56.85 dollars a barrel on the London ICE Future Exchange.