April 5 (UPI) -- Though administration officials have yet to confirm how many National Guard members they plan to send to the southern U.S. border, President Donald Trump on Thursday said he's considering sending up to 4,000 troops.
The president told reporters he'll send "anywhere from 2,000 to 4,000" to assist Border Patrol agents with guarding the border and halting what he described a "surge of illegal activity."
Regarding the cost of the deployment, Trump said the administration is "looking at it."
"We'll probably keep them or a large portion of them" there until the wall is built.
Governors from three of the four states along the Mexican border have said they'll support Trump's request to put National Guard troops there.
"Arizona welcomes the deployment of National Guard to the border," Arizona Gov. Doug Ducey tweeted. "Washington has ignored this issue for too long and help is needed. For Arizona, it's all about public safety."
Susana Martinez, the Republican governor of New Mexico who never formally endorsed Trump's presidential campaign, told the Santa Fe New Mexican through spokesman Michael Lonergan that she backs the initiative.
Lonergan said Martinez "appreciates the administration's efforts to bring states to the table as they go about taking steps to better secure our border" and supports her state's National Guard troops "fully in any mission -- state or federal at home or abroad."
The lone border-state holdout who hasn't embraced the idea is California Gov. Jerry Brown -- a Democrat who Trump criticized last week on Twitter, saying he's weak on undocumented immigration. Brown hasn't publicly criticized or endorsed the president's plan.
California National Guard spokesman Lt. Col. Tom Keegan sent a statement to McClatchy's Washington, D.C., bureau on behalf of Brown's administration, saying the governor anticipates "more detail, including funding, duration and end state" from the White House.
"This request -- as with others we've received from the Department of Homeland Security, including those for additional staffing in 2006 and 2010 -- will be promptly reviewed to determine how best we can assist our federal partners," Keegan said.
If Trump's administration needs troops from elsewhere, though, Oregon Gov. Kate Brown said he shouldn't count on help from her state. She wrote on Twitter that she does not plan to comply with the president's request to have the National Guard patrol the southern border.
"If President Donald Trump asks me to deploy Oregon Guard troops to the Mexico border, I'll say no," Brown tweeted. "As Commander of Oregon's Guard, I'm deeply troubled by Trump's plan to militarize our border."
A senior administration official told reporters Wednesday that Department of Homeland Security and Department of Defense officials were coordinating with border governors on the National Guard deployment. The official said the conversations were productive.
"This is an opportunity for these governors to embrace efforts by the federal government," the source said. "We are optimistic we will see that cooperation."
In recent days, the president has lashed out against "large caravans" of people -- mostly from Honduras -- traveling north from Mexico's southern border last week. The group, initially about 700 people in size, left the southern Mexican town of Tapachula on March 25 and grew in size as it traveled north.
"The big Caravan of People from Honduras, now coming across Mexico and heading to our 'Weak Laws' Border, had better be stopped before it gets there. Cash cow NAFTA is in play, as is foreign aid to Honduras and the countries that allow this to happen. Congress MUST ACT NOW!" Trump tweeted early Tuesday morning.
DHS Secretary Kristjen Nielsen, who announced the deployment Wednesday, didn't offer details about how the National Guard would be used along the border, but said they would serve in a similar capacity as they did when previous administrations deployed troops to the border -- aerial surveillance and support functions. The U.S. military is largely prohibited from engaging in domestic law enforcement like arresting undocumented immigrants at the border.