Crude oil prices drifted lower in early Monday trading as world leaders said from Germany more work was needed to keep the global economy moving.

British Prime Minister David Cameron said during a meeting in Germany with U.S. President Barack Obama there are many historic issues at the center of the trans-Atlantic partnership.

"But they all really come down to two words: prosperity and security -- what we want for our people back at home, which is the chance of a job, and also the chance to have greater security," Cameron said.

European leaders are working on trade deals with the United States at a time when the global economy is still recovering from recession. Moody's Investors Service said Monday that for the United Kingdom, economic growth should be robust through next year.

"However, the U.K.'s economic growth pattern remains relatively unbalanced and mainly driven by domestic demand and the services sector, while exports and manufacturing remain subdued," credit officer Kathrin Muehlbronner said in a statement.

The price for Brent, a global benchmark based on North Sea oils, suffered a modest loss in early Monday trading, down about 35 cents to $62.96 per barrel. West Texas Intermediate, the U.S. standard, lost about 43 cents, or seven- tenths of a percent, to $58.71 per barrel. Brent started June around $65 per barrel, while WTI began the month at $60.

Oil prices moved lower last week on reports of slow demand growth from members of the Organization of Petroleum Exporting Countries. OPEC opted to keep its production levels unchanged despite continued weakness in the oil market.

Mitsuhiro Furusawa, deputy managing director for the International Monetary Fund, said at a Monday investment conference at the Bank of Korea in Seoul that global economic growth was still modest and uneven nearly eight years after the financial crisis.

"The U.S. recovery is continuing, although at a slower pace this year than originally forecast, and growth in the euro area and Japan is expected to pick up," he said. "By contrast, economic performance in many other parts of the world is falling short of expectations."