The Organization for Economic Co-operation and Development on Wednesday trimmed its growth estimate for the world economy as upturn remains weak and uneven.

The Paris-based OECD in its Economic Outlook, said world real gross domestic product will expand 3.1 percent, instead of 3.4 percent estimated in November. That will be followed by 4 percent expansion in 2014, it said.

The U.S. growth outlook for 2013 was lowered to 1.9 percent from 2 percent. Across OECD countries, GDP is projected to rise by 1.2 percent this year and by 2.3 percent in 2014.

Historically high unemployment remains the most serious challenge facing governments, it observed. The OECD warned governments that urgent action must be taken to reduce unemployment, which has risen to dangerous levels in many countries.

RTTNews