Washington: US President Donald Trump said Wednesday the US is sending armed soldiers to the southern border after Mexican soldiers "pulled guns" on US troops.

Trump appeared to be referring to an April 13 incident in which Mexican troops reportedly questioned and pointed their weapons at two US troops conducting surveillance on the border.

"Mexico's Soldiers recently pulled guns on our National Guard Soldiers, probably as a diversionary tactic for drug smugglers on the Border. Better not happen again! We are now sending ARMED SOLDIERS to the Border. Mexico is not doing nearly enough in apprehending & returning!" Trump said on Twitter.