President Donald Trump on Tuesday said his administration is not considering reinstating its policy of separating children from their parents at the southern border and rejected reports that he is "cleaning house" at the Department of Homeland Security.

"We're not looking to do that," Trump told reporters during a sit-down in the Oval Office with Egyptian President Abdel Fattah El-Sisi when asked about reinstating the policy.

Trump's remarks come a day after NBC News reported that Trump for months has urged his administration to reinstate large-scale separation of migrant families crossing the border. NBC News also reported that outgoing Homeland Security secretary, Kirstjen Nielsen, resisted, setting her at odds with the president. Nielsen resigned under pressure on Sunday.

The president on Tuesday denied that he is trying to "clean house" at DHS after it was announced Monday that U.S. Secret Service Director Randolph Alles, a retired Marine Corps major general who was appointed two years ago, is on his way out the door just a day after Nielsen's resignation.

"I never said I'm cleaning house, I don't know who came up with that expression," Trump said, adding that he wants a tougher approach at the southern border to deal with migrants seeking entry into the country.

At least 2,600 children were separated from their parents under the Trump administration's "zero tolerance" policy at the border, which was in effect in 2018 from May 6 through June 20. Under pressure, Trump signed an executive order last June to end the practice and allow families to be detained together.

On Tuesday, Trump falsely claimed that President Barack Obama was the architect of the child separation policy and that the Obama administration constructed the cages in which to place separated children.

"President Obama separated the children. Those cages that were shown, I think they were very inappropriate, they were built by President Obama's administration," Trump said. "I'm the one that stopped it."

However, NBC News previously reported that claim is inaccurate — there was no widespread Obama-era policy of separating parents and children.

Elliot Williams, Obama's former deputy assistant attorney general, told MSNBC's Andrea Mitchell on Tuesday that Trump's claim is a "lie."

"I'm pretty confident that the Obama administration did not," Williams said. "The idea that this was some Obama-era thing, it's just a lie, it's factually untrue."

Trump also blamed congressional Democrats and judges who have ruled against his immigration policies for issues at the border.

"We're bucking a court system that never ever rules for us and we're bucking really bad things with the Democrats in Congress not willing to act," he said.