US President Barack Obama will brief Prime Minister Dr. Manmohan Singh along with other world leaders by tomorrow on his new Af-Pak policy that is expected to cover sending thousands of more troops to fight Taliban insurgency and outline an exit strategy. Obama's call to Dr. Singh will take place close on the heels of the two leaders' meeting in Washington during which the Afghan issue was discussed prominently. Dr. Singh had said it is important for all major regional and international players to put their weight behind the Afghan government.<br/><br/>Obama had highlighted the importance of tackling violence and extremism emanating from the region in a serious way.<br/>