"The Plan is an example of the visionary leadership necessary to reduce emissions and to tackle climate change," Ban's spokesman Stephane Dujarric told reporters.
"The Secretary-General appreciates President Obama's strong, personal leadership on climate change," he added.
"President Obama's leadership by example is essential for bringing other key countries on board and securing a universal, durable and meaningful agreement in Paris in December."
The ambitious Plan assigns each state a target for reducing its carbon pollution from power plants. States will be allowed to create their own plans to meet the requirements and will have to submit initial versions of their plans by 2016 and final versions by 2018.
Ban is travelling to Washington today to meet with Obama on a range of issues.
