"Governments, including civilian leadership, law enforcement, and the military, must work together not only within their own borders, but also with those cities facing similar issues and challenges," Verma said, speaking at the Megacity Security Conference organised by the Atlantic Council, the India Foundation here.
"The best chance we have for governing in such a complex environment is to develop domestic and international networks that enable local governments and communities to share best practises and lessons learned.
"Only through collective thought and partnership can we harness the concentration of skills and technical resources in the world's cities that will increase wealth and improve the quality of life," the US Ambassador said.
Current projections estimate India's urban population will grow more rapidly than in China, South America or the West, the US envoy said.
"In addition to India's three current mega-cities, it is expected there will be four more by 2030: Chennai, Bangalore, Hyderabad, and Ahmedabad. New Delhi is projected to become the world's second-largest city by 2030 with a population of 36 million," he said.
"Urbanisation is increasing across the world, including and especially here in India, as more and more people flock to metropolises in search of greater opportunity and a better future," he added.
Changing weather patterns and rising temperatures due to
climate change are affecting economic and living conditions, particularly in rural areas, prompting flight to cities, Verma said.
"We also see mass migrations due to conflict as endangered populations look for safer places to work and raise their families," he said.
In 1950, there were only two mega-cities: New York and Tokyo. In 1975, Mexico City became the world's third mega-city. Today, there are approximately 30 mega-cities - cities with more than 10 million people, he said.
"The ongoing shift in population from rural to urban areas is unprecedented in human history. A 100 years ago, just 2 out of 10 people lived in cities. Today, more than half of the world's population lives in cities," Verma said.
"In the early 1800s, London and Beijing were the only two cities in the world with 1 million people. Now, there are at least 450. Beyond the growing list of mega-cities, more than 40 'large' cities have populations between 5 to 10 million people.
Outside of law enforcement and security cooperation, the US is partnering to make India's cities more livable, Verma said.
"For example, we are lead partners in developing three of India's smart cities: Ajmer, Visakhapatnam, and Allahabad. Our US Agency for International Development, through the Urban India Water, Sanitation, and Hygiene Alliance, is supporting India's urban development and Clean India initiatives.
"We also are partnering for development of renewable energy sources, including investment in clean energy projects in India, and to improve air quality," he added.
