Both are keen to push forward with more such collaboration over the next two years, in areas like sharing green technologies and expertise, and spearheading regional environment initiatives.

The US State Department's Assistant Secretary for Oceans, Environment and Science Ms Claudia McMurray, was here for the biennial review of the US-Singapore Memorandum of Intent on Environmental Cooperation.

On Tuesday, her delegation met representatives from various agencies, including the Ministries of Environment and Water Resources and Trade and Industry, the Agri-Food and Veterinary Authority, the Maritime Port Authority, the National Environment Agency and the Public Utilities Board.

Ms McMurray said areas discussed included efforts to tackle the illegal regional trade in timber and wildlife, improving energy and vehicle efficiency and greater use of renewable energy.

Both sides also reviewed accomplishments made so far, including an ongoing workshop here to train port inspectors and customs authorities to identify illegal shipments of the much coveted but protected ramin wood.

Ms McMurray said the US appreciated Singapore's leadership role in the region on green issues.

Singapore, the former chair of the Asean Working Group on Environmentally Sustainable Cities, has helped link several US cities with Asian cities to share expertise in areas like clean air and water.

The memorandum 'underscores the importance placed by Singapore and the US on working together to ensure environmental sustainability, in tandem with enhancing bilateral trade and investment ties', said Ms Rosa Daniel, deputy secretary of MEWR.

It comes under the US-Singapore Free Trade Agreement, signed in 2003, which includes cooperation on environmental issues.

During their stay here, the US delegates, who left on Thursday, also visited the upcoming Marina Barrage, an 'engineering feat' which Ms McMurray said the US could look at in tackling its own water challenges.