The announcement comes as Texas Governor Greg Abbott announced his intention to increase the Texas deployment of National Guard troops to at least 1,000, KTSA-San Antonio reported.
Trump has talked about he wishes to utilize the military on the border until progress is made on his proposed border wall, which has principally stalled in Congress. Safety Secretary James Mattis last Friday authorised paying for as a lot as 4,000 Nationwide Guard personnel from the Pentagon value vary by way of the tip of September.
Administration officials have said that rising numbers of people being caught at the southern border, while in line with seasonal trends in recent years, require an immediate response. Arizona Gov. Doug Ducey, a Republican, was present to send off the first group of 225 on Monday.
The Republican governor accused the federal government of ignoring the border "for almost a decade".
Under federal law Mr Trump invoked in his proclamation calling for National Guard troops.
At a National Guard center in Phoenix, the Governor told the troops they'll make Arizona and the country safer.
Also on Friday, the Texas Army National Guard said 250 guardsmen would be deployed to the U.S. -Mexico border in the following 72 hours. New Mexico's Republican governor has said her state will take part in the operation, but hasn't announced a deployment.
California and New Mexico, the two other states bordering Mexico, have not made public commitments to sending Guard members.
The Arizona deployments began Monday. "Remember, we're going in in support roles", he said.
"I don't think this is a partisan issue or an identity issue", he said. "You current me any one who's for drug cartels or human trafficking or this ammunition that's coming over a wide-open and unprotected border proper right here".
The placement of soldiers along the border has raised some concerns about militarizing the area.
Joel Villarreal, the mayor of Rio Grande City in Texas, said he did not agree with what he characterized as "the militarization of the border".
Ducey said that misstates what the soldiers will be doing.
Those duties will include "air support, reconnaissance support, operational support, construction of border infrastructure, and logistical support".
"Under the law", said Garcia of Coalición de Derechos Humanos, "it's no different than what happened with Obama and Bush, but because it's Donald Trump who's saying we're going to build the wall ... it's more politics than anything. It gets more boots on the ground and they serve in a support capacity, which they'll be very good at". But Napier, a Republican, said such fears have been allayed.
But Abbott said he wanted to "downplay the notion" that the National Guard would be "trying to take on anybody that's coming across the border".
The troops will not have law enforcement powers but will only provide support.