(Video source: VCG)

US President Trump, speaking at a Montana campaign rally on Saturday, praised U.S. troops installing razor wire along the US-Mexico border to stop an approaching migrant caravan, saying "barbed wire, used properly, can be a beautiful sight."

Trump has fixed on the caravan and immigration as a whole taking a hardened stance in a bid to rouse his political base ahead of congressional elections on Tuesday.

The Pentagon this week said it was deploying more than 5,200 troops to the border at Trump's direction to confront the men, women and children traveling through Mexico as they flee violence and poverty in Central America. 

Trump has characterized it as an "invasion" of migrants. Mexico has said 2,800 to 3,000 people are in the caravan, which left Honduras in mid-October, although many are expected to drop off before reaching the US border.