US Navy chief Admiral Gary Roughead arrived here on Sunday on a six-day visit to explore ways to bolster naval cooperation between the two countries. During his stay in New Delhi, Admiral Roughead will have discussions with Navy chief Admiral Nirmal Verma and call on Defence Minister A K Anthony, Chief of Air Staff Air Chief Marshal P V Naik, Army Chief General V K Singh and Defence Secretary Pradeep Kumar. Admiral Roughead, Chief of the naval operations of the US Navy, will also visit various naval ships and establishments in Mumbai and Goa and some training establishments in Kochi....