Former house speaker Newt Gingrich has admitted he made a "boo boo" in claiming Donald Trump was dropping his "drain the swamp" phrase.

The president-elect responded to Gingrich's comments in a tweet on 22 December, in which he said: "Someone incorrectly stated that the phrase 'DRAIN THE SWAMP' was no longer being used by me. Actually, we will always be trying to DTS."

Gingrich had made it clear he is a fan of 'drain the swamp', stating in an interview with NPR Radio's Morning Edition that the phrase "vividly illustrates the problem, because all people in this city who are the alligators are going to hate the swamp being drained."

However, Gingrich claimed the phrase was being retired, stating: "But, you know, he is my leader, and if he decides to drop the swamp and the alligator I will drop the swamp and the alligator."

Gingrich said in a video he posted on Twitter: "I want to report I made a big boo-boo. I talked this morning with President-elect Trump, and he reminded me he likes 'draining the swamp.'"

He added: "When I make a mistake, I'm going to be straightforward and tell you. I blew that one. 'Draining the swamp' is in. President-elect Trump wants to do it. And you're going to get to be a part of it."

The open apology was immediately mocked by former independent presidential candidate Evan McMullin, who shared a link to Gingrich's apology, and wrote: "Newt is learning the public prostration required of authoritarian loyalists. The dear leader often changes his mind but he's always correct."