The international communities have to raise actions and ambitions to help the transformation to the green growth, which will require innovation, investment and collaboration by all partners, said UN Secretary-General Ban Ki-moon on Tuesday in Copenhagen.

"Achieving a clean energy transformation will need the combined efforts of governments, multilateral investment banks, private finance, civil society, the knowledge community and the private sector," Ban said in a keynote speech at the closing session of the annual Global Green Growth Forum (3GF).

Ban mentioned that he launched in September 2011 the Sustainable Energy for All initiative, which aims to achieve three inter-linked global targets by 2030: universal access to modern energy services; the doubling of energy efficiency; and the doubling of the share of renewable energy in the world's energy mix.

Ban asked leaders to bring solutions and initiatives with targets and investment plans. He also urged them to raise their level of ambition by scaling up the investments and financial flows necessary for making the transformation to a low-carbon economy.

"We need large amounts of capital for the rapid development of low-carbon infrastructure. We are seeing progress, but not fast enough. And not at sufficient scale,'' Ban said.

Ban said he is personally engaged in trying to move the financial actors, regularly meeting with financial actors and investors.

On Monday, Danish Prime Minister Helle Thorning-Schmidt said also that the collaboration among countries and the public and private sectors is essential to address the climate change.

"No actor can solve the challenges alone. Governments, investors, companies, civil society and researchers cannot do the job by themselves. We need to collaborate to succeed," said Thorning-Schmidt.

The 3GF, organized by the Danish Government in cooperation with China, Kenya, Mexico, Qatar and South Korea, aims to explore new public-private initiatives to deliver concrete actions, commitments and recommendations for the transition to long-term sustainable green growth at sale and speed.

The two-day event was convened under the headline "improving resource efficiency in the value chain" and featured discussions on promoting the efficient use of the resources during the entire life cycle of a product or a process, and minimizing the negative impact on sustainability.