International Monetary Fund (IMF) Managing Director Christine Lagarde called on world leaders to adopt a United Nations agenda for sustainable development over the next 15 years.

At an event held by the Washington-based think tank Brookings Institution, Lagarde said the weak economic outlook has made achieving world development goals more difficult than in the past. She said downside risks to global growth have increased. Lagarde stressed that the Sustainable Development Goals aim to eradicate hunger and extreme poverty, reduce inequality, achieve gender equality and take urgent action to combat climate change. "It would be a lot easier if the world was cruising at 5.5-6 percent global growth than it is at the moment," Lagarde said.

Updated in July, the IMF's Global Economic Outlook report forecast global growth of 3.3 percent this year, reducing it from 3.5 percent. Lower commodity prices, slower growth in China and a realignment of monetary policy have increased downside risks to the global economic outlook.

She also underscored that cooperation between countries can change the current difficult scene.

The U.N. Development Summit will start on Friday in New York as part of the 70th session of the United Nations General Assembly. The summit will last for three days and include the participation of Prime Minister Ahmet Davutoğlu, U.S. President Barack Obama, Russian President Vladimir Putin, Iranian President Hassan Rouhani and Chinese President Xi Jinping as well as 144 state and government leaders.