WASHINGTON, United States (AP) — President Donald Trump today eased up on his threats to shut the southern border as officials across his administration explored half-measures that might satisfy the president’s urge for action, like stopping only foot traffic at certain crossings.

Facing a surge of Central American migrants trying to enter the US, Trump last week threatened to seal the border this week if Mexico did not immediately halt all illegal immigration into the US, a move that would have enormous economic consequences on both sides of the border.

While Trump did not back off the idea completely, he said he was pleased with steps Mexico had taken in recent days and renewed his calls for Congress to make changes he contends would solve the problem.

“Let’s see if they keep it done,” he said of Mexico. “Now, if they don’t, or if we don’t make a deal with Congress, the border’s going to be closed, 100%.” He also said that he might only close “large sections of the border” and “not all of it.” He added that his posturing was “the only way we’re getting a response.”

Closing the border completely would disrupt manufacturing supply lines and the flow of goods ranging from avocados to cars, making for a “potentially catastrophic economic impact,” in the words of Republican Sen Mitch McConnell, the Senate majority leader.

Some inside the administration also worry it would only exacerbate illegal immigration.

Meantime, administration officials grappled with how they might minimise the impact of a shutdown or implement less sweeping actions.

White House economic adviser Larry Kudlow, for example, told CNBC he’s been looking at potentially keeping truck lanes open.

“We are looking at different options, particularly if you can keep those freight lanes, the truck lanes, open,” he said. As for the hundreds of thousands of tourists and workers who cross the border legally, Kudlow said, “that may be difficult.”

Earlier, White House press secretary Sarah Sanders had told reporters that, while, “Eventually, it may be that it’s the best decision that we close the border,” the president was “not working on a specific timeline” and all options remained on the table. The Council of Economic Advisers, she said, was conducting a number of studies on the impact, and “working with the president to give him those options.”

White House spokesman Hogan Gidley said in an appearance on MSNBC that closing only certain entry ports, or parts of all of them, could be among the steps short of closing the entire border.