Donald Trump flatly denied on Tuesday that he was planning a “big” new crackdown on migrants at the southern border, even as senior administration officials briefed reporters on the details of such a plan in the works, leaders in charge of immigration policy were shuffled, and insiders described Trump in private as apoplectic over a recent increase in migrant arrivals.

A senior official told reporters the White House was crafting a plan that would target asylum-seekers anew and possibly bring back a version of Trump’s deeply unpopular policy of family separations.

Under a prospective policy the administration calls “binary choice”, migrant parents would be forced to choose between being detained with their children in jail-like facilities or agreeing to a separation under which children would be taken out of detention and placed with a guardian or in a shelter, the senior official said.

Immigration rights groups warned that the proposals could lead to egregious new violations of international obligations and constitutional law.

“We’re obviously very disturbed to hear these reports,” said Charanya Krishnaswami of Amnesty International USA, speaking to the Guardian from near the San Ysidro port of entry in California.

“There’s already been a relentless, multi-faceted attack on asylum seekers. The idea that they’re somehow going to enact greater restrictions and make it worse, it’s just hard for me to imagine what that would even look like.”

Trump’s gathering initiative at the southern border, which was signaled on Sunday by the announcement that the homeland security secretary, Kirstjen Nielsen, would be stepping down, appeared to be the result of presidential frustration, possibly the election calendar and the news last week that 103,000 migrants had arrived at the border in March, the highest total in more than a decade.

In one White House meeting last month, an anonymous attendee told CNN, Trump was “ranting and raving, saying border security was his issue” and demanding a port of entry at El Paso, Texas, be closed, only to have Nielsen talk him out of it.

Then the firings started. On Sunday, Trump tweeted that Nielsen was out. On Monday, Trump fired a second top homeland security official, the director of the secret service. Last week, Trump withdrew his nominee to head US Immigration and Customs Enforcement (Ice), saying he wanted someone “tougher”.

In spite of the visible churn and the background briefings, Trump denied before the cameras, in a spontaneous exchange with reporters at the White House on Tuesday, that he was planning a significant new move on immigration.

“We have to close up the borders,” Trump said, during a meeting with Egyptian president Abdel-Fattah El-Sisi. “We’re not doing anything very big.”

Trump also denied he was considering a new family separations policy, saying: “We’re not looking to do that.”

But the exchange with reporters was otherwise so saturated with falsity and misdirection that the actual state of play was left in doubt.

Trump claimed to have ended the family separation policy, as opposed to implementing it, saying: “President Obama had child separation. Take a look. The press knows it, you know it, we all know it. I didn’t have, I’m the one that stopped it. President Obama had child separation.”

Trump also described the family separation policy favorably: “Now I’ll tell you something, once you don’t have it, that’s why you see many more people coming. They’re coming like it’s a picnic, because, ‘Let’s go to Disneyland.’”

Any unilateral move on immigration policy in the form of an executive order or presidential proclamation is sure to run into legal challenges. A judge in San Francisco on Monday blocked a Trump policy from January of returning asylum seekers to Mexico while their cases are processed, a wait that could take months or years.

The “remain in Mexico” policy lacked sufficient protections to ensure migrants do not face “undue risk to their lives or freedom” in Mexico, the judge, Richard Seeborg, said.

Without action by Congress, which has declined to join Trump in most every one of his immigration initiatives, the administration’s legal options for altering policy are limited, said the Cornell University Law School professor Stephen Yale-Loehr, co-author of a 21-volume immigration law treatise.

The quickest legal way for Trump to accelerate the deportation of asylum-seekers, said Yale-Loehr, could be by expanding a process known as expedited removal, which could allow for deportations of migrants arrested within 100 miles of the border up to 14 days after crossing.

“But they would have to do that through a rule – they couldn’t just announce it,” Yale-Loehr said. “And so it would take some time to go through the rule-making process.”

Aaron Reichlin-Melnick, a policy analyst at the American Immigration Council, said it was hard to discern the Trump administration’s overarching legal strategy.

“They’ve certainly been engaging with Congress on this,” Reichlin-Melnick said, “but it’s hard to say, with the chaos going on in the administration right now, whether they’re truly focused on finding solutions inside the [Department of Homeland Security], or whether they’re really hanging their hat on Congress as their only hope.”

Yale-Loehr said: “This administration doesn’t seem to have a coherent policy.

“It seems that the president simply wants to score political points by seeming to be tough on immigration without really thinking through the best way to get to the root cause of why people are fleeing violence in Central American countries to come to the United States.

“The rules are already stacked against immigrants in trying to stay in the United States, and this administration is trying to make it even harder but without thinking through the consequences.”



