President Donald Trump said he will be announcing a 'very dramatic' action at the border, without specifying exactly what it would be.

Trump said he was not moving to close the southern border – a threat he made in March amid one in a series of surges of immigrants at the U.S. border with Mexico.

He ultimately backed off after venting that Mexico was 'doing NOTHING' to stop the flow of illegal immigrants and a trio of Central American countries also 'do Nothing.'

'This is a big-league statement, but we are going to do something very dramatic on the border because people are coming into our country, the Democrats will not give us laws, they will not change laws, they will not meet they will not do anything,' Trump said at the White House on Thursday.

President Donald Trump said he would give a major speech and do something 'very dramatic' at the southern border

He brought up the speech when asked whether he would respond to a restrictive abortion law in Louisiana.

As he does during his campaign rallies and other events, Trump accused Democrats of wanting 'open borders' and wanting 'drugs pouring into our country, asserted that they 'want to have crime' and 'want to have human trafficking.'

He said he was going to make the statement 'probably tomorrow but maybe today.'

Central American migrants heading in caravan to the US are pictured on Tapachula, State of Chiapas, Mexico, on April 15, 2019

Central American migrants heading in caravan to the US walk towards Huixtla, on Tapachula, State of Chiapas, Mexico, on April 15, 2019

Workers build a border fence in a private property located in the limits of the US States of Texas and New Mexico taken from Ciudad Juarez, Chihuahua state, Mexico on May 26, 2019

He spoke as he headed off to Colorado to speak at the Air Force Academy commencement.

Asked if he was closing the borders, Trump said no, but then said 'we're doing something else.

He said it will have to do with people 'illegally coming over the border,' saying it would be 'my biggest statement so far on the border.'

Trump has acted unilaterally to reprogram billions of dollars from military functions to border construction at the U.S.-Mexico border, although some of his actions are tied up in court.

Trump has considered using the U.S. Insurrection Act to deploy additional U.S. troops, which might be a way to get around posse comitatus restrictions on using the military for domestic purposes.

The 1807 law allows the president to use guard and military forces to put down an internal 'unlawful obstruction or rebellion.'

Earlier this month, Trump tweeted: 'All people that are illegally coming into the United States now will be removed from our Country at a later date as we build up our removal forces and as the laws are changed.'

He added: 'Please do not make yourselves too comfortable, you will be leaving soon!'