PHOENIX -- Arizona Gov. Doug Ducey says 225 National Guard members are heading to the Mexico border to back President Trump's fight against illegal immigration. "These troops will be helping our federal partners with any support role responsibilities that they need," Ducey tweeted Monday, and said more troops will arrive at the border on Tuesday.

These troops will be helping our federal partners with any support role responsibilities that they need, and will be stationed in both the Tucson and Yuma sectors. https://t.co/5qB2kiV1RP — Doug Ducey (@dougducey) April 9, 2018

Texas has also said it will send National Guard members to the border.

Mr. Trump signed a proclamation last week directing states to send National Guard troops to the U.S.-Mexico border. In a memo, Mr. Trump said the "situation at the border has now reached a point of crisis." The document orders the secretary of defense to support the Department of Homeland Security in securing the southern border to stop the flow of drugs and people, and it orders the agency heads to submit a report within 30 days outlining what other steps can be taken.

Mr. Trump has been frustrated by slow action on building his "big, beautiful wall" along the Mexican border -- the signature promise of his campaign -- as well as a recent uptick in illegal border crossings, which had plunged during the early months of his presidency. He has also been upset because the spending bill he grudgingly signed last month includes far less money for the wall than he'd hoped for.

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Astrid Dominguez, director of the ACLU Border Rights Center, said in a statement that the president "is trying to create a crisis where there is none. This is another impulsive reaction to not getting his wall fully funded and a maneuver to distract the American public from the crisis he created for 800,000 young immigrants when he ended DACA, whose lives and futures are at risk."

In 2010, President Obama sent 1,200 National Guard troops to the border, and President George W. Bush sent 6,000 in 2006.