President Donald Trump said Thursday he will, soon, sign an executive order aimed at ending asylum for undocumented migrants to stop them from getting a “free pass” into the United States with “meritless claims.” He also warned members of two migrant groups to put down their rocks — or else.

Trump also warned the caravan that he has ordered thousands of U.S. military troops to the southern border to assist law enforcement personnel in preventing them from touching American soil. The commander in chief issued a not so veiled threat, saying all U.S. law enforcement and military personnel at the southern border will treat rocks that might be thrown by members of two migrant caravans approaching the U.S.-Mexico border as “a firearm.”

He did not say whether American personnel and troops would be cleared to fire on any rock-throwers. Video and photographs chronicling two groups’ march from Central America through Mexico have captured some caravan members hurling rocks at Mexican security officials. Trump claims some have been badly injured, though there are scant media reports from the ground of widespread rock-caused wounds.

Trump made those announcement and threats during an impromptu question-and-answer with reporters after remarks on immigration and an approaching Central American caravan that mostly repeated claims and statements he has made in the last few weeks.

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He said his administration “is finalizing” a plan to end asylum for undocumented migrants, which would be implemented when he signs any order. He has before said he would take a proposed action in the next calendar week only for those things to be delayed weeks, months, or simply put back on the shelf seemingly in perpetuity.

But the Roosevelt Room event featured one more immigration-related announcement sure to rankle Democratic lawmakers and candidates — and likely some moderate Republicans.

“We will hold them, for a long time if we have to,” Trump said of migrants who enter the United States illegally and without a legitimate asylum request.

But the president did not say how many more federal law enforcement personnel might be needed or how long this indefinite detention would cost. He also did not say whether he would seek emergency funding from Congress for any new costs of that “tent city” detention program or if he wants any needed funds in a Homeland Security Department spending measure that must be negotiated when Congress returns for a lame duck session.

As he often does, the GOP president slammed Democrats, claiming they will not vote for any immigration overhaul legislation. As usual, he excluded a fact that, for him, is inconvenient, especially five days before a crucial election that will shape his presidency: 54 Senate Democrats voted for a 2013 overhaul bill that passed that chamber overwhelmingly before dying in the House.

Many congressional Democrats have harshly criticized Trump’s rhetoric about the caravan and moves like ordering active-duty military troops to perform a police action on U.S. soil. They see a purely political stunt aimed at riling up the GOP base.

For instance, House Intelligence ranking member Adam Schiff of California, who could become its charman if Democrats take over that chamber, said Sunday it appears the Pittsburgh synagogue shooter believed Trump’s claims that wealthy Jewish individuals were helping finance the group.

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“This shooter also apparently believed that Jews were funding this caravan,” Schiff told CNN. “And so when the president and supporters of his or people around him attack George Soros and say Soros is funding this caravan, they are trafficking in a well-known and historic anti-Semitic trope.”

Asked about such Democratic concerns, Trump denied talking about the Central American caravans and floating potential actions is just a political stunt before Tuesday’s midterms. But in almost the next breath, he said “women [voters] want security.”

And on a diplomatic note, State Department spokeswoman Heather Nauert is under “serious consideration” to become the next U.S. ambassador to the United Nations, Trump said.

Notably, she is a former anchor and reporter on Fox News, the president’s favorite news network.