Advertisement apologises after being booed at gig for calling Ireland part of UK has offended Irish fans by greeting them as the UK. (PA) has apologised to Irish fans after on stage comments referring to Ireland as part of the UK that led to him being booed during a gig - something he called an "honest airhead embarrassing mistake".

The performer was in Salthill, Galway with his group Black Eyed Peas on Saturday, but found the crowd's excitement at seeing him quickly turned to boos which he later discovered was because of a gaffe in greeting them.

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US singer and The Voice UK mentor, who spends much of his time in the UK for work, apparently repeatedly referred to Ireland as being a part of the UK, offending fans who were at the show.

He offered his sincere apologies after his mistake was pointed out to him, repeatedly replying to tweets with: "I’m so sorry for that mistake…Please forgive my ignorance & accept my apology…#LOVE…"

(l-r), J. Rey Soul, Taboo and of the Black Eyed Peas attend the 2022 Latin American Music Awards at the Michelob ULTRA Arena at Mandalay Bay Resort and Casino in Las Vegas, Nevada on April 21, 2022 -- (Photo by: Bryan Steffy/Telemundo/NBCU Photo Bank via Getty Images) and the Black Eyed Peas were playing a show in Galway. (NBCU Photo Bank via Getty Images)

The star also later replied to another person's criticism of his comments by tweeting: "You’re 1000% correct…It’s not confusion…I spend lots of time in this part of the world to know the difference…todays mess up was honest airhead embarrassing mistake…& I’m sorry…the republic of Ireland fought for their independence…and that’s inspiring…#LOVE"

Correcting him on his comments during the gig, one person tweeted: "dude, Ireland isn't in the UK, a lot of people died to make that happen"

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Someone else tweeted to the US hitmaker: "Out at the Black Eyed Peas gig out in Salthill and @iamwill keeps saying UK and the crowd are booing! But look, it's an easy mistake for any Canadian."

He was reportedly made aware of his mistake when a fan was shown on the big screen by the stage holding up a message explaining his error. at the Voice Kids 2019 Photocall held at The Royal Society of Arts, London. offered his sincere apologies for his error. (PA)

One person tweeted: "At the Galway show, Will I Am said Ireland is in the UK multiple times before a girl held up a phone (shown on the big screen) with 'WE ARE NOT THE UK' on it."

Someone else wrote: "The Black Eyed Peas have been on for all of 5 mins and http://WILL.I.AM has made 3 comments about Ireland being in the UK… there will be a RIOT tonight."

Another person commented: "My great grandfather did not fight in the 1916 Rising just so could claim that Ireland was a part of the UK."

It isn't the only time has fallen foul of a crowd while speaking on stage recently - last month, he was at a digital marketing event in Hamburg and retweeted one of the audience who posted quoting him: "'It’s a special thing to us, this… city in Germany' bare minimum, sufficient compliment for Hamburg by @iamwill"

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