Three liberal states are teaming up to fight climate change in response to President Trump withdrawing from the Paris climate agreement.

California, Washington and New York, which together account for a fifth of the country's economy, say they're committed to upholding the goals of Paris despite Trump's pullout.

"The president has already said climate change is a hoax, which is the exact opposite of virtually all scientific and worldwide opinion," California Gov. Jerry Brown (D) said in a joint statement from himself and the other two states' governors.

"I don't believe fighting reality is a good strategy - not for America, not for anybody. If the President is going to be AWOL in this profoundly important human endeavor, then California and other states will step up.

The three states are already some of the most progressive in policies regarding greenhouse gas emissions and aim to lead the world on fighting climate change.

Brown and Washington Gov. Jay Inslee (D) attended the Paris climate conference in 2015, where nearly 200 nations wrote the pact to limit greenhouse gas emissions.

The coalition, which the governors are dubbing the "U.S. Climate Alliance," is launching without specific goals, except to do their own parts to abide by the original United States commitment.

"I am proud to stand with other governors as we make sure that the inaction in D.C. is met by an equal force of action from the states," said Inslee. "Today's announcement by the president leaves the full responsibility of climate action on states and cities throughout our nation."

New York Gov. Andrew Cuomo (D) accused the Trump administration of "abdicating its leadership and taking a backseat to other countries."

Cuomo said he is signing an executive order on climate change, which he said would confirm "New York's leadership role in protecting our citizens, our environment, and our planet."