Kai Trump looks unrecognizable in adorable throwback photo as she celebrates grandfather Donald's 80th birthday

Kai Trump looked unrecognizable in a childhood snap in which she posed with grandad Donald Trump.

The promising young golfer, now 19, shared an adorable throwback photo as she celebrated the president's milestone 80th birthday on social media.

Included in a carousel of images posted to Instagram was a baby-faced Kai, who appeared to be no older than 10.

The youngster, who is the daughter of Donald Trump Jr and Vanessa Trump, grinned a toothy smile as she stood next to her grandpa, who also beamed at the camera.

Kai proudly marked Trump's birthday on June 14 by posting eight photos of the pair together over the years. 

Besides the cute throwback, she also revealed the pair enjoying spending time on the golf course as well as another showing them sitting together on a private jet.

Captioning the upload, she wrote: 'Happy 80th birthday Grandpa, I love you so much. So excited to celebrate today with you at UFC 250.'

Kai's special tribute attracted a wave of comments.

'So sweet! Happy Birthday!' one wrote as another said, 'You have the coolest grandpa! I love that you get to share so many awesome memories with him.'

Of her childhood snap, a third continued: 'The last one is so cute.'

Trump celebrated his milestone birthday at UFC Freedom 250, with the bash ending inside the octagon on the White House's South Lawn.

As is usually the case whenever Trump attends UFC events, plenty of his family were on hand - including Kai.

He was joined by daughter Ivanka, her brothers Donald Jr and Eric as well as their wives, Bettina and Lara.

Although the event was named in honor of the country's upcoming 250th birthday, Sunday was also aimed at celebrating Trump as he entered his ninth decade.

So, while much of the night was spent honoring service members and raising money for veterans' charities, there were also helpings of praise and gifts heaped upon the President.

Just last week, Kai found herself in the middle of an editing controversy after fans noticed that boos were removed from a video she posted of herself and her grandad Trump at a Knicks game.

Kai had joined the president for Game 3 of the NBA Finals at Madison Square Garden on June 8, but their appearance was not well received by the crowds.

In footage from the night, boos - described as 'thunderous' by the official White House pool report - rang out around the arena for approximately 10 seconds when the cameras cut to Trump.

The president appeared to take the negative reaction in stride and raised a wry smile to the crowd as he saluted.

He then put his fist in the air as Grammy Award-nominated artist Avery Wilson sang the national anthem.

His granddaughter Kai also seemingly smirked at the heckling as the pair watched on from behind protective screens.

But Kai's social media upload appeared to paint a different picture as the negative response was seemingly edited out.

On June 10, she posted a 15-second clip where only applause could be heard. 

Amidst the scrutiny, video company 15 Seconds of Fame told Page Six that they had altered the sound on the clip before sending it to Kai to post.

'The video shared by Kai Trump on Instagram was exactly the clip delivered by 15SOF to her account on our app and at no time did she request that any audio be altered, enhanced, replaced or otherwise manipulated,' a company spokesperson said.

'Due to various broadcast, licensing, and contractual restrictions, 15SOF frequently cannot distribute original event audio and instead utilizes automated alternate contextual audio tracks as part of our content-delivery process. 

'The audio selection process is entirely automated and is not directed by individual users.'