Ireland’s taoiseach has denounced anti-immigration comments made by Conor McGregor as the MMA fighter visited the White House before a St Patrick’s Day meeting with Donald Trump.

McGregor said “Ireland is on the cusp of losing its Irishness” and that an “illegal immigration racket” was “running ravage on the country”.

Last week, Donald Trump singled out “Conor” – who last year was found liable for sexual assault after a civil trial – as one of his favourite Irish people.

Dressed in a green business suit to mark Ireland’s national day, McGregor was at the White House at Trump’s invitation and participated in an impromptu Q&A session with reporters. “There are rural towns in Ireland that have been overrun in one swoop,” he said, speaking in the White House briefing room alongside the president’s press secretary, Karoline Leavitt.

The 36-year-old former Ultimate Fighting Championship (UFC) champion said he was “here to raise the issue and highlight it” and that he would be listening to Trump on immigration – one of the president’s main areas of focus as he seeks to ramp up deportations of people in the US without proper documentation.