Through the initiative, Citi will engage with clients to identify opportunities to finance greenhouse gas reductions and resource efficiencies in sectors such as sustainable transportation.

It will also finance infrastructure improvements that increase access to clean water, manage waste and promote green housing.

“For more than 200 years, Citi's mission has been to enable progress by facilitating economic growth and financing transformative projects. The core mission hasn't changed, but the way we approach it has. Incorporating the principles of sustainability into everything we do improves our own operations, enhances our clients' work, and contributes to a better world,” Citi CEO Michael Corbat said.

According to James Alexander, head of the finance and economic development initiative at C40 Cities Climate Leadership Group, reducing carbon emissions and becoming more climate resilient is a key priority and major challenge for the world's megacities and their business communities

"C40's ongoing partnership with Citi is helping global cities overcome their climate finance challenges. Today's announcement from Citi will add further opportunities to help cities achieve their climate targets, and allow businesses to become more sustainable,” he said.

Citi's effort builds on a $50 billion goal set in 2007, which was met three years early in 2013.

The initiative is also part of a new five-year sustainability commitment that focuses on environmental and social risk management and sustainability goals for Citi's own businesses and operations.

Citi has established new environmental footprint goals for 2020, including 35% reduction in greenhouse gas emissions, 30% reduction in energy and water use and 60% reduction in waste, all against a 2005 baseline.