(CNN) President Donald Trump said Tuesday that he's calling on the military to guard the US-Mexico border until his long-promised border wall is complete.

"I told Mexico, and I respect what they did, I said, look, your laws are very powerful, your laws are very strong. We have very bad laws for our border and we are going to be doing some things, I spoke with (Defense Secretary James) Mattis, we're going to do some things militarily. Until we can have a wall and proper security, we're going to be guarding our border with the military. That's a big step," he said during a luncheon with leaders of the Baltic states.

He continued: "We cannot have people flowing into our country illegally, disappearing, and by the way never showing up for court."

Asked to clarify his comments during a joint news conference, Trump said he is "preparing for the military to secure our border" and he would be attending a meeting on the topic of border security with Mattis and others "in a little while."

Trump has privately floated the idea of funding construction of a border wall with Mexico through the US military budget in conversations with advisers, two sources confirmed to CNN last week . His remarks Tuesday come on the heels of multiple days of hardline immigration rhetoric from the Trump White House, with the President calling on Congress to pass strict border laws in a series of tweets beginning Sunday.

Read More