US President Barack Obama spoke to Prime Minister Manmohan Singh over phone and discussed regional and international issues of mutual interest, including the raging Eurozone crisis.In a statement yesterday, the White House said that the two leaders agreed to work to strengthen the global economy to cope with shocks from the Eurozone. The statement said, the leaders agreed on the importance of steps to strengthen the resilience of the global economy in response to persistent risks in the Eurozone and elsewhere and on focusing on measures to boost global growth.The President and the Prime Minster also agreed to work closely together towards a successful two-day G-20 Summit in Los Cabos, Mexico, from June 18. The 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.