President Donald Trump went full HGTV mode Thursday … unloading on an ABC reporter for asking why he’s focused on D.C. renovations instead of the Iran war.

The fiery exchange went down near the Lincoln Memorial, where the POTUS was showing off plans for his Washington makeover … while the shaky Iran ceasefire and soaring gas prices continue dominating headlines.

That’s when ABC News correspondent Rachel Scott asked why he’s so focused on beautification projects during the conflict … and Trump had quite the fiery response.

Trump immediately responded, “Because I wanna keep our country beautiful and safe. Beautiful also.”

He then launched into a rant about the condition of the National Mall’s reflecting pool area … claiming crews had to remove “11 or 12 truckloads of garbage” from the water near the memorials because the nation’s capital had become “filthy.”

But the real fireworks came when Trump turned directly on Scott.

“Such a stupid question that you asked,” Trump snapped … before adding, “This is one of the worst reporters. She’s with ABC fake news and she’s a horror show.”

Trump kept rolling … defending the renovations by declaring, “Beauty made our country. People made our country great.”

And this wasn’t their first tense exchange either.

Back in January, Trump also took aim at Scott after another press scrum … saying, “She hasn’t asked me a good question in years.”