New Hampshire's Republican governor says he won't join an alliance set up by other states pledging to uphold the Paris climate change accord.

The Concord Monitor reports Gov. Chris Sununu said, "Not at this time, especially when we do not yet know its impact on our economy and environment." Sununu said he's made cleaning up groundwater a priority and remains committed to New Hampshire's "long and proud tradition of responsible environmental stewardship."

The state's also is part of the Regional Greenhouse Gas Initiative to reduce emissions.

The U.S. Climate Alliance was formed after Republican President Donald Trump said last week that the U.S. would withdraw from the Paris climate change agreement reached by 195 countries last year.

California, New York and Washington started the alliance. Nine more states and Puerto Rico joined Monday. Members pledge to reduce emissions 26 to 28 percent from 2005 levels.