Attorney General (AG) Bob Ferguson of the U.S. state of Washington Thursday threatened to take legal action against a federal government's declaration of a national emergency to build a wall on the U.S.-Mexico border.

Washington Attorney General Bob Ferguson [File Photo: AP]

Ferguson said he will take steps to block the intended action announced by President Donald Trump earlier in the day to declare a national emergency to obtain funds for his long-promised border wall.

President Trump is ready to take executive action -- including a national emergency -- to "ensure we stop the national security and humanitarian crisis at the border," White House Press Secretary Sarah Huckabee Sanders said in a statement Thursday.

However, Ferguson accused the president of exceeding his authority in violation of the Constitution.

"Declaring a state of 'emergency' to build his wall is unlawful. We are working with members of our congressional delegation to determine if this action depletes federal funds flowing to Washington," Ferguson said.

"If Washington is harmed, my office will take appropriate steps to block this unlawful action," he added.

The Washington AG has sued the Trump administration 33 times in the past over various legal disputes.

Also on Thursday, Washington state governor Jay Inslee called Trump's declaration "an alarming and legally dubious attempt" to sidestep the constitutional authority granted to Congress.

He said he felt outraged by Trump's "abuse of power."

"This declaration doesn't do a single thing to make our nation safer. All it does is further divide Americans, erode our system of checks and balances, and advance the president's agenda of fear and misinformation," Inslee said.

The fight over the funding for the U.S.-Mexican border wall between the White House and congressional Democrats led to a record-breaking 35-day federal government shutdown last month, which ended late January.

A national emergency declaration, which would allow Trump to bypass Congress and use the military to build the wall, is widely expected to spark lawsuits challenging the president's authority.