SACRAMENTO, Calif. — Three Democratic governors said Thursday they won't let the United States back away from a commitment to reduce greenhouse gas emissions, despite President Donald Trump decision to withdraw from an international pact.

"This is an insane move by this president," California Gov. Jerry Brown said, blasting the decision as "deviant behavior from the highest office in the land."

Brown joined Gov. Jay Inslee of Washington state and Gov. Andrew Cuomo of New York to form the U.S. Climate Alliance to uphold the Paris climate agreement, a pact involving nearly 200 nations aimed at slowing the warming of the planet.

The three states already belong to an emissions reduction pact of states and cities worldwide, but Thursday's action marked a direct stand against the Trump administration and a formal commitment to upholding the targets of the Paris agreement.

Connecticut Gov. Dan Malloy and Virginia Gov. Terry McAuliffe also expressed interest in joining the new pact.

"We governors are going to step into this cockpit and fly the plane," Inslee told reporters. "The president wants to ground it — we're going to fly it."

Trump formally announced his decision to leave the historic international agreement after months of teasing the action. He criticized the pact as a job-killer that put the United States as an unfair advantage.

It may be years, however, before the country can formally exit the deal, but Trump said he'll immediately halt implementation. He said he would consider re-entry if the U.S. could get a better deal.

Republican politicians and representatives of the coal industry cheered Trump's action.

"President Trump's courageous decision to exit the Paris Accord recognizes that the United States is not legally bound to an Obama-era agreement that set unrealistic emissions targets at the expense of billions of American taxpayer dollars without the approval of Congress," said Texas Attorney General Ken Paxton, who joined nine other states in urging Trump to leave the agreement.

Under the Paris agreement, negotiated during former President Barack Obama's tenure, the United States voluntarily committed to reducing polluting emissions by 1.6 billion tons by 2025.

The Democratic governors' new pact commits to that same goal, which requires a 26 to 28 percent reduction in emissions from 2005 levels.

Specific targets haven't been set for each state. California, New York and Washington together account for about 10 percent of the country's greenhouse gas emissions, Brown's office said.

California is already working to reduce greenhouse gas emissions by 40 percent from 1990 levels by 2030, and Brown has cast himself as Trump's chief foil on climate policy. It's unclear when discussions between the three governors began, but they announced their new pact within an hour of Trump's announcement.