UN chief Ban Ki-moon made a call to double global consumption of renewable energy over the next two decades in order to ensure sustainable economic development.
"It's possible if we show political leadership," Ban said about the goal that falls under a sustainable energy initiative aiming to have universal access to power by 2030. Currently, renewable energy accounts for about 16 percent of world consumption.
"We have to be very austere in using energy... We have to completely change our behavior, at home, at the office," the UN secretary-general added at an event hosted by the Center for Global Development think-tank in Washington.
About 1.3 billion people on Earth -- a fifth of the global population -- lacks access to electricity, while 2.7 billion do not have clean fuel to cook their food and heat their homes, relying instead on open fires or furnaces that burn coal, wood or animal waste.
"Energy is central to jobs, transport, water, sanitation... climate," Ban said after meeting with finance ministers from the G20 most powerful economies.
The United Nations is expecting some 120 heads of state and government to attend the Rio+20 meeting on sustainable development in Brazil in June, with a focus on developing a plan for implementation and action.
On Monday, the European Union vowed fresh funds Monday to help developing nations provide sustainable energy to 500 million people by 2030.
European Commission president Jose Manuel Barroso pledged 50 million euros ($65 million) over two years for technical assistance and said EU nations would seek hundreds of millions of euros more to support investments in sustainable energy for developing countries.
Speaking at the Center for Global Development event, Danish Development Cooperation Minister Christian Friis Bach noted that fossil fuels received four to five times more subsidies worldwide than renewable energy.
The think-tank issued a report coinciding with the event saying the US government should play a key role in helping meet the UN targets.
"The United States is the logical country to lead an effort to address these problems, given the size of its venture capital and investment community, the prominence of its financial markets and exchanges, and its tradition of support for business-oriented agencies," it said in a statement.