Expo 2017 Astana, with the theme of "Future Energy," was inaugurated Friday with an opening speech by Kazakh President Nursultan Nazarbayev, and with a lights and fireworks show that lit up the sky of the Central Asian nation's ultramodern capital.

"An exposition on this scale is the result of the global community working together," Nazarbayev said at the opening ceremony.

The international event aims to be a magnetic center that binds together ideas from participating countries and organizations on types of alternative and renewable energy.

"Humanity is on the point of creating a highly efficient source of energy, and our expo will contribute to the development of clean energy. Millions of Kazakhs and thousands of foreign guests wil get to know and understand the latest trends and ideas," the Kazakh leader said at the Congress Center.

"Sustainable energy solutions aren't easy to find. They're the result of years of work, development and collaboration. Today, Expo 2017 Astana allows us to join forces and work together for the future," the president of the Bureau of International Expositions (BIE), Steen Christensen, said.

Seventeen heads of state and government from around the world, including King Felipe VI of Spain and leaders of the Shanghai Cooperation Organization member countries, consisting of Russia, China, Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan, Pakistan and India, attended the inauguration.

One object of the visitors' admiration is the Nur Alem pavilion, symbol of the expo and the world's largest spherical construction measuring 80 meters (262 feet) in diameter.

Also onstage to amaze was a multimedia show at the capital's Congress Center with robots and humans moving in perfect harmony to act out the energy theme with a contemporary aesthetic.

"More than 1,000 cultural events enliven the expo. Visitors can learn a lot about the culture and history of the Kazakh people, enjoy traditional Kazakh song and dance, as well as visit other corners of Kazakhstan," Nazarbayev said.

Entertainment will also include 71 acts by the Cirque du Soleil, designed especially for the expo, at a price of 12 to 18 euros, plus concerts by Placido Domingo, Steve Aoki, Eros Ramazzotti, Afrojack and more.

The international exposition is expected to attract from 2 million to 5 million visitors.

Expo 2017 Astana seeks to reflect the importance of progressing toward a worldwide energy system based more and more on types of renewable energy, which will help reduce CO2 emissions, end dependence on oil and increase the energy autonomy of the different regions and communities of the world.