U.S. President Donald Trump asserted Tuesday he had an "absolute right" to declare a national emergency to build a wall along the U.S.-Mexico border without congressional approval of funding for it.
Sixteen states sued Trump late Monday in federal court in California where judges have overturned other Trump initiatives during his 25-month presidency.
But the U.S. leader said at the White House, "I think we're going to do very well with the lawsuit."
As he announced the national emergency last Friday, Trump said he expected to lose the initial legal fights over the declaration, especially if the lawsuits disputing his decision were filed in the 9th Circuit of western state courts, which is where the 16 states sued. But Trump said he expects to ultimately prevail with a favorable Supreme Court ruling overturning any adverse lower court decisions.
In earlier Twitter comments, the U.S. leader targeted California Tuesday for its leading role in the multistate lawsuit.
Trump cited California Gov. Gavin Newsome's cancellation last week of a high-speed rail line between Los Angeles and San Francisco, claiming, without evidence, the cancellation was due to "world record setting" cost overruns. Trump also claimed the project was "hundreds of times more expensive than the desperately needed Wall!"
California Attorney General Xavier Becerra responded to those comments with his own tweet.
"President Trump, keep talking... we continue to gather evidence to support our lawsuit against you. #FakeNationalEmergency."
The states' complaint alleges Trump's emergency declaration is illegal and unconstitutional, and harms the states and their residents by taking money away from anti-drug programs, military construction projects and other law enforcement efforts. Trump is planning to reallocate $8 billion in funding from various U.S. agencies to build the border wall.
The lawsuit asks the court to permanently prohibit the Trump administration from diverting the funds from elsewhere in the government, or to build a wall without Congress appropriating money for that purpose.
Becerra accused Trump of engaging in "theater" and hyping a crisis because he failed to get Congress or Mexico to pay for the wall, a favorite campaign vow of Trump during his successful 2016 run for the presidency.
Trump's emergency declaration has been met by a number of other lawsuits, including from Texas landowners who could see the wall go through their property.
WATCH: Trump condemns lawsuits
On Tuesday, the American Civil Liberties Union filed a suit on behalf of the Sierra Club and the Southern Border Communities Coalition arguing the president failed to meet the requirements to declare a national emergency.
"In fact, there was and is no national emergency to justify the president’s action, only his disagreement with Congress’s duly enacted decisions on the extent and pace of spending on the border wall," the lawsuit says.
Another group, Citizens for Responsibility and Ethics in Washington, also filed a suit seeking documents about the Trump administration's legal reasoning for declaring the emergency.