Mexican National Guard members stand along the banks of the Suchiate River in Ciudad Hidalgo, Mexico, to prevent illegal crossings across the border river to and from Tecun Uman in Guatemala. –  AFP Photo

General Vicente Antonio Hernandez told reporters that in addition to the Suchiate River deployment, members of the country's National Guard were also deployed at 61 migrant crossings in the southern state of Chiapas.

The general added that since May, 20,400 migrants had been "rescued" from organised crime and 30 human traffickers arrested.

"We would be very irresponsible if we continue to let them go on," he said, recalling the case of a Salvadoran migrant who drowned with his toddler daughter while trying to cross the Rio Grande to reach the United States.

Trump threatened in May to impose tariffs on all Mexican goods if the country did not do more to slow the flow of Central American migrants crossing the US-Mexican border.

After a week of tense negotiations, the two sides announced a deal on June 7 under which Mexico agreed to send thousands of National Guardsmen to secure its borders and expand its policy of taking back asylum-seekers while the US processes their claims.

The migration deal appears to be delivering Trump's desired result so far: the number of migrants taken into custody at the southern US border is expected to drop by 25 percent for June, the acting head of the Department of Homeland Security, Kevin McAleenan, said on Friday.

Trump tweeted his thanks to Mexico on Wednesday, saying that it is "doing a far better job than the Democrats on the Border." – AFP