White House press secretary Sarah Sanders softened the White House’s threat to close the southern border by the end of the week, saying Tuesday that such a move was not President Trump’s “first choice” and that he does not have a “specific timeline.”

“Eventually it may be the best decision that we close the border,” Sanders told reporters at the White House, adding that Mexico has taken some concrete steps to slow the flow of migrants coming into the United States, as Trump has demanded.

“He’s hoping that Mexico will continue to step up, like we’ve seen them do over the last couple of weeks,” Sanders said. “We hope that that continues, and that we can work with them so we don’t have to [close the border].”

Asked what date the president has in mind for a possible border closure, Sanders said that “the president’s not working on a specific timeline.”

Since Friday, when Trump first leveled his threat, the White House has repeatedly been warned by economists and lawmakers in both parties that closing the border would inflict immediate economic damage on U.S. consumers and businesses.

“The president has spent the last two years helping build up this economy and helping create the boom we have,” Sanders told reporters Tuesday. “He certainly doesn’t want to hurt that. But at the same time, his number one job as the president is to protect life and to protect Americans.”

In tweets Friday, Trump said that if Mexico didn’t “immediately stop ALL illegal immigration coming into the United States” from the southern border, he would close it, or at least portions of it, by the end of this week.

“If they don’t stop them, we’re closing the border,” Trump said at an event in Florida later that afternoon. “We’ll close it. And we’ll keep it closed for a long time. I’m not playing games. Mexico has to stop it.”

White House officials doubled down on the threat as they appeared on Sunday talk shows.

Acting White House chief of staff Mick Mulvaney said on ABC News’s “This Week” that it would take “something dramatic” to persuade the president to abandon his border-closing plans. And White House counselor Kellyanne Conway insisted on “Fox News Sunday” that the president’s threat “certainly isn’t a bluff.”

Speaking to reporters Tuesday, Sanders continued to blame Democrats for what she characterized as a mounting crisis at the border.

“Our first choice would be for Democrats to actually sit down with us and help fix a broken system to address the national security and humanitarian crisis that exists at our border,” Sanders said.

Since Friday, Trump has tweeted several times about immigration but has made no mention of a potential border closure.