Ireland's prime minister Micheal Martin tested positive for Covid-19, the country's ambassador to the United States said, forcing him to leave a gala event attended by Joe Biden, AFP reports.

Martin, who holds the position known as the Taoiseach in Ireland, is in Washington and was due to meet President Biden at the White House today to mark St Patrick's Day.

He was pictured sitting next to House speaker Nancy Pelosi at the Ireland Funds Gala event at the National Building Museum in the US capital shortly before leaving when a PCR test returned positive.