The issue has drawn a host of prominent GOP figures: former President Donald Trump was expected to travel to the border this week and Republican governors from Florida, Nebraska and Iowa have all committed to sending law enforcement officers for border security.
Texas Gov. Greg Abbott this month announced plans to build more barriers along the border.
Abbott’s new push has been criticized as political theater, but he has defended the plan, saying the number of border crossers remains high.
The governor said he will use $250 million in state money and crowdsourced financing for the barriers, although the timeline and cost for the push are unclear.
It also faces potential court challenges from the federal government.
Large numbers of migrants have shown up at the U.S. border with Mexico, with many turning themselves over to U.S. Border Patrol agents in seeking legal asylum status.
Encounters with single adults have remained high, with arrests of sex offenders at the border up by 542%.
More than 250,000 border crossers have evaded capture so far this year, according to the Border Patrol.
A private donation will fund the cost of sending the South Dakota National Guard troops, Noem said.
The deployment is expected to last from 30 to 60 days, while the other states involved are sending law enforcement officers for roughly two-week stints.
Noem, who is seen as a potential presidential contender, drew a distinction between her decision to send the National Guard and other governors who are sending state police officers.
“The border is a national security crisis that requires the kind of sustained response only the National Guard can provide,” she said in a statement. “We should not be making our own communities less safe by sending our police or Highway Patrol to fix a long-term problem President Biden’s Administration seems unable or unwilling to solve.”
The governor’s office did not immediately respond when asked for the identity of the private donor paying for the National Guard deployment.
Meanwhile, the South Dakota Democratic Party slammed the governor’s use of National Guard troops, tweeting: “Politicizing the military is a line that should never be crossed. Kristi Noem is using our National Guard for her personal benefit.”
Adapted from reporting by Associated Press.