Prime Minister Manmohan Singh on Saturday left for a eight-day tour of Mexico and Brazil to attend the G-20 and Rio+20 summits.
Singh will attend the seventh summit of the Group of 20 developed and developing countries(G-20) starting in the Mexican resort town of Los Cabos on June 18 and the Rio+20 Summit in Rio De Janeiro.
The G-20 summit is likely to be dominated by the crisis in Europe, which - combined with slowing growth in China and India - poses a threat to the world economy.
The ongoing European sovereign debt crisis has made it difficult or impossible for some countries like Greece and Spain in the euro area to re-finance their government debt without the assistance of third parties.
The Rio Summit, commencing on June 20, is being held 20 years after the first Earth Summit, a landmark gathering, in a renewed bid to rally the world behind a common environmental blueprint.