Transcript for Trump signs order authorizing National Guard to protect border
President trump's decision to send troops to the Mexican order. A white house memo Cal this a point of crisis. Critics are raising questions about the scope of the order and Cecilia Vega starts us off with the latest. Good morning, Cecilia. Reporter: Good morning to you. President trump likes to very much tout that historic low number of peoplellegally crossing T borderince he took office. Aides now say those numbers appear to be back on the rise. They are worried this so-called trump effect might be wearing off and their fix, send in the National Guard. This morning, governors from border states like Texas and Arizona welcoming the president's push to send in the nation guard in the fight against illegal imgration. Saying help is needed but in lifornia, not S fast. Offials there say we look forward to more detail and so far that is something the trump adnistration is short on. They won't say how many too, how long they'll be deployed or the cost. It will be strong. It will be as man as is needed to fill the gaps. Reporter: The new national Guard order comes a day after president trump surprised his own advisers with this idea. We're going to be guarding our Borr with the military. Reporter: U.S. Tops are barred from arresting illegal border crossers, but past presidents have use the National Guard to support the border patrol with things like inlligence gathering. Aides say the president wants those troops at the border immediately because his frustrated. Now the wte house facing questions about the sudden sense of urgency and whether it sms from reports about a caravan of Central American migrants heading north tough Mexico. Ev though many of those migrants sayhey have no intention of crossing into the U.S. Does this have anything to do th the report that the president saw on Texas news. I think it has everything to do with protecting the people of this country. Reporter: As for his wall, after the president suggested he might try to use military funds to build it which would take an act of congress, the white house tried to clarify. We're looking intoptions for the military to build a wall on mility installations on the border. Reporter: We checked. Pentagon officials tell ABC news the military does not actually own land on the u.s./mexico border. Now, Mexico says it has been assured by the administration that the nional guard troops will not be armed and will not serve as border patrol agents. They do warn, though, tt if thiseployment rests in a militarization of the border, that quote, it would seriously damage the bilateral relationship. Gege, Mexico's foreign minister is in town for meetings with the administration. This is certainly going to make forome awkward talks. The president is vocal over the last week about getting U.S. Troops out of Syria right away. Very soon. His administration has pushe back against that and now reached some Sor of compromise? Reporter: Yeah, but there have been pretty testy exchanges behind the sceneith his own national security team. Among those opposing the president, his new pick for the secretary of state Michael Pompeo. This own advisers are saying it notealistic to have U.S. Troops witrawn from Syria in the S months that the president nts. The president always against time lines, about getting the job done. Paula.
This transcript has been automatically generated and may not be 100% accurate.