New Delhi, Dec 07 (ANI): Union External Affairs Minister Sushma Swaraj on Sunday said that the United Nations will soon declare June 21 as World Yoga Day following a proposal by Prime Minister Narendra Modi. Addressing the 'Gita Prerna Mahotsav', organized "to celebrate 5,151 years of religious book Gita" at the Red Fort Maidan in New Delhi, Sushma said that yoga is not merely an exercise, but a road to prosperity and good health.