WASHINGTON — Frustrated by Congress’ refusal to provide funds for more than a modest length of border wall, President Donald Trump declared Tuesday that he will deploy U.S. troops to the frontier with Mexico.

He also dramatically scaled back his demand for a barrier along the border, saying he wants a wall along just “700 to 800 miles” — a far cry from what he led supporters to expect.

Militarizing the border would likely escalate tensions with Mexico, which is in the midst of a presidential campaign in which a leading candidate has vowed to ensure that his country is no longer a “piñata” for foreign powers. Trump has been threatening to scrap NAFTA — both to secure more favorable trade terms, and to pressure Mexico to curb the flow of its own citizens and migrants from Central and South America.

But Trump’s inability to deliver on his signature campaign promise has left backers deflated and the president himself openly flustered. He briefly threatened to veto the $1.3 trillion budget deal over the shortage of wall funds.

Trump vowed throughout the 2016 campaign to build a “big, beautiful wall” along the 1,954-mile U.S.-Mexico border, and his rhetoric was widely regarded as a call for a full-length barrier.

About 654 miles of the border is already fenced, so Trump’s new goal represents only a modest expansion. Congress provided $1.6 billion in the recent $1.3 trillion omnibus budget, enough to add 33 miles and for replacement barrier along twice that length.

“We have $1.6 billion, and we’re starting brand-new sections of walls. But we need to have a wall that’s about 800 miles — 700 to 800 miles of the 2,000-mile stretch. We have a lot of natural boundaries,” Trump said at a White House meeting, with Defense Secretary Jim Mattis at his side.

Trump has generally been vague about many miles of barrier he envisions. Last July, he told reporters aboard Air Force One as he flew to Paris that he wants “anywhere from 700 to 900 miles of see-through wall.” The remarks were initially off the record but the White House later agreed to release them.

Trump’s Delusion