WASHINGTON — President Donald Trump spoke at the U.S.-Mexico border in California on Friday, warning that "our country is full" and cannot accommodate any more immigrants.

"The system is full. We can't take you anymore,” Trump said at a roundtable event with law enforcement officials and local leaders at a border patrol station in Calexico. "Our country is full...Turn around."

He added, "When it's full, there's nothing you can do. You have to say, 'I'm sorry, we can't take you.'"

Trump also reiterated his willingness to impose auto tariffs on Mexico or close the border if the flow of migrants at the southern border does not decrease. However, the president also expressed hope that he would not need to do so and thanked Mexico for doing more in the last four days "than they have ever done" to stem the number of people reaching the border.

"They're apprehending people now by the thousands and bringing them back to their countries, bringing them back to where they came from," Trump said of Mexico.

Trump also said he plans to make significant progress on the border wall construction in the next two years.

"We expect to have close to 400 miles done within about two years from now. That's a lot — 400 miles will cover most of it," he said at the roundtable meeting, promising that a barrier along the border would deliver results.

"What we've done and what we're doing, you're gonna see some very, very strong results and as soon as the barriers or the walls — I like calling them walls 'cause that's what they are — go up, you're gonna have a tremendous impact."

Border patrol agents presented Trump with a plaque mounted on a portion of the border wall thanking him for proudly defending the American border: and for his "unwavering support for the men and women" on the front lines.

The president wrapped up his border visit Friday with a stop at the newly constructed border wall, which he described as a "concrete protector" and "anti-climb." The refurbished wall now stands at 30 feet tall and runs 2.25 miles long.