Oil prices increased on Monday as concerns on eurozone crisis eased after Greece offered a fresh cash-for-reforms proposal.

Brent crude for August delivery increased 8 cents at $63.10 a barrel, while front month US crude rose 6 cents higher at $59.67 a barrel, Reuters reported.

Oil prices dipped nearly 2% on Friday over worries about the debt default, before recovering following a tweet by a European Commission official on Monday to say that the latest Greece proposal was a ‘good basis for progress’.

Crude prices ended higher as foreign creditors were provided with new reform package by the Greek Prime Minister Alexis Tsipras in a bid to prevent default on €1.6bn in debt repayments in June to the International Monetary Fund.

Although the oil prices edged-up, it could not go higher due to concerns over high domestic US oil production, which produced around 9.6 million barrels per day.

Despite a decline in the total number of active rigs in the US last week, worries over high domestic oil output increased as Friday’s data revealed that oil producers in the US added a rig each in the Permian and Bakken shale basins during the week.

The news agency quoted Morgan Stanley saying in a research note that ten million barrels of unsold crude specifically from Nigeria are held in offshore storage even during strong summer demand.